Updated Books.php
Updated Calendar.php
Add stub .travis.yml
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
Updated YouTube.php
Add support for Travis CI

Uses Travis to run tests against PHP 5.3, 5.4 and 5.5.
Merge pull request #134 from ithinkihaveacat/travis-support

Automatically run tests on Travis CI
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