Semantic Version your Gemfile

If you're following semantic versioning in your Gemfile, then why not make it explicit.

If you want Rails 3.2 then just say that;

gem "rails", "~> 3.2.x"

If you want RSpec 2 (but not 3 quite yet) then just say that;

gem "rspec", "~> 2.x"

If you want any version of Newrelic, then don't version it;

gem "newrelic_rpm"

If you need exactly Ember 1.0.0.rc7, then say that;

gem "ember-source", "1.0.0.rc7"