Don't require @ prefix for attachment filenames
Allow any data type for custom data
Return non-JSON response data
Merge pull request #64 from travelton/master

Removed legacy PHP closing braces
Merge pull request #60 from jchamberlain/raw-response

Return non-JSON response data
Merge pull request #57 from jchamberlain/custom-data

Allow any data type for custom data
Merge pull request #56 from jchamberlain/master

Don't require @ prefix for attachment filenames
Merge branch 'master' of https://github.com/mailgun/mailgun-php into travis/merging