Removed support for 'dataWrapper' feature.

This feature would cause the library to incorrectly parse responses containing a 'data' field.
Renamed 'data' to 'modelData'

Resources containing a 'data' field were incorrectly created because of the clash in the variable name.
Fixed calculation of headers' size in test
Re-calculate headers' size after stripping proxy string
Lint fixes
Add Travis CI build status badge
Merge pull request #135 from ithinkihaveacat/badge-readme

Add Travis CI build status badge to README
Merge pull request #133 from silvolu/master

Spring cleaning
Added service Mapsengine.php
Updated AndroidPublisher.php
Added service Dns.php
Added service QPXExpress.php
Updated Analytics.php
Remove duplicate lowercase QpxeExpress.php
Merge pull request #136 from tagged/remove-dupe-qpx-class

Remove duplicate lowercase QpxeExpress.php
Use refresh token when revoking access if available

Previously we would only ever use the access token, which may have expired.
Now, use the refresh token preferentially if present.
Use single quotes on $ sign

Avoids potential issue on older PHP. Fixed #128
Fixing collection to use new private modelData
Merge pull request #138 from ianbarber/master

Fixing token revoking and change URI template quoting
Set a default value for array and map types