Added return status checks when building list of pinned public keys
Added return status checks when handling connection's authentication challenge
Fix bug where examples always used AFSSLPinningModeNone
Remove all _AFNETWORKING_PIN_SSL_CERTIFICATES_ conditions

Fixes #1098
Update documentation re: _AFNETWORKING_PIN_SSL_CERTIFICATES_
Remove reference to _AFNETWORKING_PIN_SSL_CERTIFICATES_
Add adn certificate to Mac example
Use new httpbin image request to fix image test.
Restore execution of tests under Travis
Switch Travis build script to leverage xctool 0.1.7, which supports implicit dependencies. Simplify xctool invocation
Merge pull request #1128 from blakewatters/bugfix/restore-travis

Restore execution of tests under Travis
Merge pull request #1100 from dstnbrkr/remove-conditional-compilation

Remove conditional compilation (_AFNETWORKING_PIN_SSL_CERTIFICATES_)
Add tests for some functionality in [AFHTTPClient initWithBaseURL]
Merge pull request #1099 from lixar/safety-checks

Added safety checks for OSStatus value returned by SecXXX functions
[Issue #1099] Removing if statements before CFRelease calls
Moving __unused signifier into parameter type
Fixing static analyzer warnings about CFRelease calls to NULL pointer