Tweak bootstrap rake task description

Identified by @bradleypriest in #129.
updated readme to reflect bootstrap behavior
adds class_option for passing ember_path

complete with tests for other non-tested generators
changes to ruby 1.8 hash syntax
changes to ruby 1.8 hash syntax
uses custom path for generator testing
adds some missing requires
Merge pull request #143 from mtylty/adds_generator_class_option_for_custom_ember_path

adds class_option for passing ember_path from the command line
Merge pull request #138 from theandym/master

Updated README.md to match ember:bootstrap output
Merge pull request #130 from jroes/patch-2

Tweak bootstrap rake task description