Improved security of OptInHandler.
Merge pull request #31 from travelton/ImproveOptInSecurity

Improved security of OptInHandler.
Fixed typo for including an Exception
Merge pull request #41 from Milannv/patch-1

Fixed typo for including an Exception
Move mocks

Created a Mocks directory to seperate mocks from classes.

I moved Mailgun\Tests\MailGunTest to Mailgun\Test\Mocks\Mailgun. As it's not a
test it's a mock. So shouldn't be suffixed with Test.

I mocked Mailgun\Tests\Connection\TestBroker to Mailgun\Tests\Mocks\Connection\TestBroker as it's a mock and should be with other mocks.
Fix fatal error in not finding exception.

Tried to throw MissingRequiredMIMEParameters which didn't exist in current namespace or added via use. Connection exceptions was included by MissingRequiredMIMEParameters is in messages exceptions so changed the added exception name to messages.

Exception message constant didn't exist. So added it.
Move fclose and unlink to before the return so they're actually called.
Removed pointless try and catch. None of the functions threw an exception and it was just rethrowing. Also Exception didn't exist in that namespace
Removed apiKey member since it's not used anywhere.
Add tests to ensure exceptions are flung and fixed wrong variable name used
Fix php 5.3 compat
Whitespace changes. (Probably some PSR-2 stuff as well
Comment out possible php bug failure
Merge pull request #42 from icambridge/fixAllTheThings

Fixed Fatal error and Warnings added tests
Add setMessage
Apply coding style that is in src
Fix 5.3 compat
Merge pull request #44 from icambridge/setMessage

Add setMessage to MessageBuilder
Depend on guzzle  >=3.8

As guzzle 3.9.* is out, mailgun should support it as well - else it
creates conflicts on larger projects.
Merge pull request #45 from tarjei/master

Depend on guzzle  >=3.8