Update dependencies

Update to be compatible with latest version of ChefSpec
Remove Strainer and use Rake instead
Update Berkshelf to ~>3.0
Setup travis matrix

Attempt to set travis matrix to run kitchen only on on rvm
version (2.0.0 here)
Attempt to fix kitchen command
don't run chefspec twice with rvm version 2.0.0
Fixed rubocop

RuboCop 0.28 released yesterday :)
Merge pull request #4 from Numergy/travis-matrix

Travis matrix
Merge pull request #3 from Numergy/update-dependencies

Update dependencies