Changes handlebars dependency, adds tests, corrects asset include, bumps version

* Changes handlebar gem dependency to handlebars_assets
* Adds includes for JavaScript library gems so they load via the asset pipeline
* Corrected mozart-all manifest to use handlebars.runtime
* Updated gem description
* Corrected usage information in generator to match README
* Added tests for gem class constants
* Bumped gem version
Added Travis-CI build configuration
Travis-CI runs the :default task, so add :test as a dependency
Adds badges for various data points
Added switch in Gemfile, corrected class constant

* Added version switch for railties gem version for Ruby versions < 1.9
* Corrected the class constant used for comparison in test
Added switch to handle Rails versions prior to 3.1
Removed ruby-head for the time being

* Dying on Travis-CI with Unable to download data from https://rubygems.org/ - no such name (https://rubygems.org/latest_specs.4.8.gz)
Merge pull request #5 from sgerrand/switch-handlebars-dependency

Changes handlebars dependency, adds tests, corrects asset include, bumps version to 1.0.2
Merge pull request #6 from sgerrand/adds-travis-ci-configuration

Adds tests, Travis-CI configuration and code data badges