Use uniform .ruby-version file

* Add .ruby-version (supported by all major version managers).
* Remove .rbenv-version (rbenv checks .ruby-version first).
* Update .rvmrc:
  * Create .rvmrc via RVM's command.
  * Remove extra commented lines from .rvmrc.
  * Setup .rvmrc to pull ruby version from .ruby-version file.
Remove .rvmrc

Gemset support is not as crticical as it used to be. Remove .rvmrc as RVM
uses .ruby-version by default if no .rvmrc is present.
Merge pull request #398 from stevenhaddox/ruby-version-updates

Use uniform .ruby-version file
Replace underscores for hostnames in Vagrantfile

Virtualbox will not complain, but silently die with "The following SSH command responded with a non-zero exit status.
Vagrant assumes that this means the command failed: service hostname start"
Merge pull request #402 from rb2k/patch-1

Replace underscores for hostnames in Vagrantfile
Ensure the git user is set during CI
Merge pull request #406 from RiotGames/travis-git-user

Ensure the git user is set during CI
Added feature to automatically generate cookbooks with built-in support for chef-minitest. Tests included.

When cookbook command is given --chef_minitest option, Berkshelf will now generate empty chef-minitest files and include the minitest-handler in the run_list of the Vagrantfile.
Accidentally left a redundant template file in the generator_files directory
Uncommenting broken test in init_generator_spec.rb
Berksfile modified to wrap a group around minitest-handler, so that upload can be done without deploying cookbook to server.
Bugfix, ensure that libraries aren't created with invalid characters in name.
Merge branch 'chef-minitest' of github.com:charlesjohnson/berkshelf into chef-minitest