Added a License to the gemspec - Fixes emberjs#3050

Author: wagenet

ember-source.gemspec

@@ -9,6 +9,7 @@ Gem::Specification.new do |gem|
   gem.summary       = %q{Ember.js source code wrapper.}
   gem.description   = %q{Ember.js source code wrapper for use with Ruby libs.}
   gem.homepage      = "https://github.com/emberjs/ember.js"
+  gem.license       = 'MIT'
 
   gem.version       = Ember.rubygems_version_string