Add .ruby-version, Gemfile and chefspec
Add encoding to metadata.rb
Add simple specs for default recipe

* Chefspec kept complaining (rightfully) about the attribute assignments
in the recipe, so they were moved to the kafka attributes file instead.
* Create user with correct gid and home directory.
* Change mode of directories to '755' instead of 00755.
* Change mode of init.d script to '755' instead of 00755.