Handle empty files gracefully. Also, rcov was causing problems with ruby 1.9 and recommends upgrading to simplecov.
Merge pull request #5 from AdamFerguson/master

I noticed that yettings crashes when there is a blank yetting file.
typo
Update lib/yettings.rb

Avoiding
undefined method `each' for nil:NilClass
error if Yetting is used in one of the non default environments (anything else than production, test and development).

For example this will let you run migrations in a non default environment, e.g.
rake db:migrate RAILS_ENV=myenv
Merge branch 'master' of git://github.com/laph/yettings

Conflicts:
	lib/yettings.rb
	test_app/spec/yettings_spec.rb