Check curl errno() and throw Exception

Without this, it may gives seemingly unrelated error as attached below.

The actual error is : "SSL certificate problem, verify that the CA cert is OK. Details:
error:14090086:SSL routines:SSL3_GET_SERVER_CERTIFICATE:certificate verify failed" because I'm running a self-signed certificate on localhost.

That raises another question though: how would we configure the transport setting?

```
Warning: get_class() expects parameter 1 to be object, resource given in /home/rachman/work/core/cake_2.0/lib/Cake/Utility/Debugger.php on line 579

Call Stack:
    0.0003     726248   1. {main}() /home/rachman/work/personal/deploy/croogo/webroot/index.php:0
    0.0457    7267832   2. Dispatcher->dispatch() /home/rachman/work/personal/deploy/croogo/webroot/index.php:96
    0.0555    8996680   3. Dispatcher->_invoke() /home/rachman/work/core/cake_2.0/lib/Cake/Routing/Dispatcher.php:162
    0.1818   20213552   4. Controller->invokeAction() /home/rachman/work/core/cake_2.0/lib/Cake/Routing/Dispatcher.php:187
    0.1818   20214608   5. ReflectionMethod->invokeArgs() /home/rachman/work/core/cake_2.0/lib/Cake/Controller/Controller.php:486
    0.1818   20214664   6. SocialitesUsersController->login() /home/rachman/work/core/plugins/2.0/socialites/Controller/SocialitesUsersController.php:0
    0.1825   20300872   7. AuthComponent->login() /home/rachman/work/core/plugins/2.0/socialites/Controller/SocialitesUsersController.php:35
    0.1826   20300952   8. AuthComponent->identify() /home/rachman/work/core/cake_2.0/lib/Cake/Controller/Component/AuthComponent.php:547
    0.1834   20365240   9. OpauthAuthenticate->authenticate() /home/rachman/work/core/cake_2.0/lib/Cake/Controller/Component/AuthComponent.php:698
    0.1840   20485480  10. Opauth\Opauth->run() /home/rachman/work/core/plugins/2.0/socialites/Controller/Component/Auth/OpauthAuthenticate.php:25
    0.1852   20714624  11. Opauth\Opauth->callback() /home/rachman/work/core/plugins/2.0/socialites/Vendor/opauth/opauth/lib/Opauth/Opauth.php:113
    0.1852   20714624  12. Opauth\Strategy\Croogo\Strategy->callback() /home/rachman/work/core/plugins/2.0/socialites/Vendor/opauth/opauth/lib/Opauth/Opauth.php:136
    0.1853   20716096  13. Opauth\Transport\Base->get() /home/rachman/work/core/plugins/2.0/socialites/Opauth/Strategy/Croogo/Strategy.php:84
    0.1853   20717520  14. Opauth\Transport\Curl->request() /home/rachman/work/core/plugins/2.0/socialites/Vendor/opauth/opauth/lib/Opauth/Transport/Base.php:68
    0.1933   20721144  15. ErrorHandler::handleError() /home/rachman/work/core/cake_2.0/lib/Cake/Error/ErrorHandler.php:0
    0.1934   20730800  16. Debugger->outputError() /home/rachman/work/core/cake_2.0/lib/Cake/Error/ErrorHandler.php:200
    0.1987   20761840  17. Debugger::exportVar() /home/rachman/work/core/cake_2.0/lib/Cake/Utility/Debugger.php:765
    0.1987   20761920  18. Debugger::_export() /home/rachman/work/core/cake_2.0/lib/Cake/Utility/Debugger.php:473
    0.1988   20762216  19. Debugger::_object() /home/rachman/work/core/cake_2.0/lib/Cake/Utility/Debugger.php:504
    0.1988   20762744  20. get_class() /home/rachman/work/core/cake_2.0/lib/Cake/Utility/Debugger.php:579


Warning: get_object_vars() expects parameter 1 to be object, resource given in /home/rachman/work/core/cake_2.0/lib/Cake/Utility/Debugger.php on line 585

Call Stack:
    0.0003     726248   1. {main}() /home/rachman/work/personal/deploy/croogo/webroot/index.php:0
    0.0457    7267832   2. Dispatcher->dispatch() /home/rachman/work/personal/deploy/croogo/webroot/index.php:96
    0.0555    8996680   3. Dispatcher->_invoke() /home/rachman/work/core/cake_2.0/lib/Cake/Routing/Dispatcher.php:162
    0.1818   20213552   4. Controller->invokeAction() /home/rachman/work/core/cake_2.0/lib/Cake/Routing/Dispatcher.php:187
    0.1818   20214608   5. ReflectionMethod->invokeArgs() /home/rachman/work/core/cake_2.0/lib/Cake/Controller/Controller.php:486
    0.1818   20214664   6. SocialitesUsersController->login() /home/rachman/work/core/plugins/2.0/socialites/Controller/SocialitesUsersController.php:0
    0.1825   20300872   7. AuthComponent->login() /home/rachman/work/core/plugins/2.0/socialites/Controller/SocialitesUsersController.php:35
    0.1826   20300952   8. AuthComponent->identify() /home/rachman/work/core/cake_2.0/lib/Cake/Controller/Component/AuthComponent.php:547
    0.1834   20365240   9. OpauthAuthenticate->authenticate() /home/rachman/work/core/cake_2.0/lib/Cake/Controller/Component/AuthComponent.php:698
    0.1840   20485480  10. Opauth\Opauth->run() /home/rachman/work/core/plugins/2.0/socialites/Controller/Component/Auth/OpauthAuthenticate.php:25
    0.1852   20714624  11. Opauth\Opauth->callback() /home/rachman/work/core/plugins/2.0/socialites/Vendor/opauth/opauth/lib/Opauth/Opauth.php:113
    0.1852   20714624  12. Opauth\Strategy\Croogo\Strategy->callback() /home/rachman/work/core/plugins/2.0/socialites/Vendor/opauth/opauth/lib/Opauth/Opauth.php:136
    0.1853   20716096  13. Opauth\Transport\Base->get() /home/rachman/work/core/plugins/2.0/socialites/Opauth/Strategy/Croogo/Strategy.php:84
    0.1853   20717520  14. Opauth\Transport\Curl->request() /home/rachman/work/core/plugins/2.0/socialites/Vendor/opauth/opauth/lib/Opauth/Transport/Base.php:68
    0.1933   20721144  15. ErrorHandler::handleError() /home/rachman/work/core/cake_2.0/lib/Cake/Error/ErrorHandler.php:0
    0.1934   20730800  16. Debugger->outputError() /home/rachman/work/core/cake_2.0/lib/Cake/Error/ErrorHandler.php:200
    0.1987   20761840  17. Debugger::exportVar() /home/rachman/work/core/cake_2.0/lib/Cake/Utility/Debugger.php:765
    0.1987   20761920  18. Debugger::_export() /home/rachman/work/core/cake_2.0/lib/Cake/Utility/Debugger.php:473
    0.1988   20762216  19. Debugger::_object() /home/rachman/work/core/cake_2.0/lib/Cake/Utility/Debugger.php:504
    0.1991   20763104  20. get_object_vars() /home/rachman/work/core/cake_2.0/lib/Cake/Utility/Debugger.php:585


Warning: Invalid argument supplied for foreach() in /home/rachman/work/core/cake_2.0/lib/Cake/Utility/Debugger.php on line 586

Call Stack:
    0.0003     726248   1. {main}() /home/rachman/work/personal/deploy/croogo/webroot/index.php:0
    0.0457    7267832   2. Dispatcher->dispatch() /home/rachman/work/personal/deploy/croogo/webroot/index.php:96
    0.0555    8996680   3. Dispatcher->_invoke() /home/rachman/work/core/cake_2.0/lib/Cake/Routing/Dispatcher.php:162
    0.1818   20213552   4. Controller->invokeAction() /home/rachman/work/core/cake_2.0/lib/Cake/Routing/Dispatcher.php:187
    0.1818   20214608   5. ReflectionMethod->invokeArgs() /home/rachman/work/core/cake_2.0/lib/Cake/Controller/Controller.php:486
    0.1818   20214664   6. SocialitesUsersController->login() /home/rachman/work/core/plugins/2.0/socialites/Controller/SocialitesUsersController.php:0
    0.1825   20300872   7. AuthComponent->login() /home/rachman/work/core/plugins/2.0/socialites/Controller/SocialitesUsersController.php:35
    0.1826   20300952   8. AuthComponent->identify() /home/rachman/work/core/cake_2.0/lib/Cake/Controller/Component/AuthComponent.php:547
    0.1834   20365240   9. OpauthAuthenticate->authenticate() /home/rachman/work/core/cake_2.0/lib/Cake/Controller/Component/AuthComponent.php:698
    0.1840   20485480  10. Opauth\Opauth->run() /home/rachman/work/core/plugins/2.0/socialites/Controller/Component/Auth/OpauthAuthenticate.php:25
    0.1852   20714624  11. Opauth\Opauth->callback() /home/rachman/work/core/plugins/2.0/socialites/Vendor/opauth/opauth/lib/Opauth/Opauth.php:113
    0.1852   20714624  12. Opauth\Strategy\Croogo\Strategy->callback() /home/rachman/work/core/plugins/2.0/socialites/Vendor/opauth/opauth/lib/Opauth/Opauth.php:136
    0.1853   20716096  13. Opauth\Transport\Base->get() /home/rachman/work/core/plugins/2.0/socialites/Opauth/Strategy/Croogo/Strategy.php:84
    0.1853   20717520  14. Opauth\Transport\Curl->request() /home/rachman/work/core/plugins/2.0/socialites/Vendor/opauth/opauth/lib/Opauth/Transport/Base.php:68
    0.1933   20721144  15. ErrorHandler::handleError() /home/rachman/work/core/cake_2.0/lib/Cake/Error/ErrorHandler.php:0
    0.1934   20730800  16. Debugger->outputError() /home/rachman/work/core/cake_2.0/lib/Cake/Error/ErrorHandler.php:200
    0.1987   20761840  17. Debugger::exportVar() /home/rachman/work/core/cake_2.0/lib/Cake/Utility/Debugger.php:765
    0.1987   20761920  18. Debugger::_export() /home/rachman/work/core/cake_2.0/lib/Cake/Utility/Debugger.php:473
    0.1988   20762216  19. Debugger::_object() /home/rachman/work/core/cake_2.0/lib/Cake/Utility/Debugger.php:504


Warning: ReflectionObject::__construct() expects parameter 1 to be object, resource given in /home/rachman/work/core/cake_2.0/lib/Cake/Utility/Debugger.php on line 592

Call Stack:
    0.0003     726248   1. {main}() /home/rachman/work/personal/deploy/croogo/webroot/index.php:0
    0.0457    7267832   2. Dispatcher->dispatch() /home/rachman/work/personal/deploy/croogo/webroot/index.php:96
    0.0555    8996680   3. Dispatcher->_invoke() /home/rachman/work/core/cake_2.0/lib/Cake/Routing/Dispatcher.php:162
    0.1818   20213552   4. Controller->invokeAction() /home/rachman/work/core/cake_2.0/lib/Cake/Routing/Dispatcher.php:187
    0.1818   20214608   5. ReflectionMethod->invokeArgs() /home/rachman/work/core/cake_2.0/lib/Cake/Controller/Controller.php:486
    0.1818   20214664   6. SocialitesUsersController->login() /home/rachman/work/core/plugins/2.0/socialites/Controller/SocialitesUsersController.php:0
    0.1825   20300872   7. AuthComponent->login() /home/rachman/work/core/plugins/2.0/socialites/Controller/SocialitesUsersController.php:35
    0.1826   20300952   8. AuthComponent->identify() /home/rachman/work/core/cake_2.0/lib/Cake/Controller/Component/AuthComponent.php:547
    0.1834   20365240   9. OpauthAuthenticate->authenticate() /home/rachman/work/core/cake_2.0/lib/Cake/Controller/Component/AuthComponent.php:698
    0.1840   20485480  10. Opauth\Opauth->run() /home/rachman/work/core/plugins/2.0/socialites/Controller/Component/Auth/OpauthAuthenticate.php:25
    0.1852   20714624  11. Opauth\Opauth->callback() /home/rachman/work/core/plugins/2.0/socialites/Vendor/opauth/opauth/lib/Opauth/Opauth.php:113
    0.1852   20714624  12. Opauth\Strategy\Croogo\Strategy->callback() /home/rachman/work/core/plugins/2.0/socialites/Vendor/opauth/opauth/lib/Opauth/Opauth.php:136
    0.1853   20716096  13. Opauth\Transport\Base->get() /home/rachman/work/core/plugins/2.0/socialites/Opauth/Strategy/Croogo/Strategy.php:84
    0.1853   20717520  14. Opauth\Transport\Curl->request() /home/rachman/work/core/plugins/2.0/socialites/Vendor/opauth/opauth/lib/Opauth/Transport/Base.php:68
    0.1933   20721144  15. ErrorHandler::handleError() /home/rachman/work/core/cake_2.0/lib/Cake/Error/ErrorHandler.php:0
    0.1934   20730800  16. Debugger->outputError() /home/rachman/work/core/cake_2.0/lib/Cake/Error/ErrorHandler.php:200
    0.1987   20761840  17. Debugger::exportVar() /home/rachman/work/core/cake_2.0/lib/Cake/Utility/Debugger.php:765
    0.1987   20761920  18. Debugger::_export() /home/rachman/work/core/cake_2.0/lib/Cake/Utility/Debugger.php:473
    0.1988   20762216  19. Debugger::_object() /home/rachman/work/core/cake_2.0/lib/Cake/Utility/Debugger.php:504
    0.1995   20764192  20. ReflectionObject->__construct() /home/rachman/work/core/cake_2.0/lib/Cake/Utility/Debugger.php:592
```