Switching from deprecated mock to double

DEPRECATION: mock is deprecated. Use double instead

https://github.com/rspec/rspec-mocks/blob/2-14-maintenance/lib/rspec/mocks/example_methods.rb#L36
Switching from deprecated stub! to stub

DEPRECATION: stub! is deprecated. Use stub instead.
Adding ruby 2.0.0 to travis build
Removing version fix from em-websocket
Revert "Removing version fix from em-websocket"

This reverts commit bf91c0d3e039819f1f8fe22191f4aacca01a304a.
Merge pull request #252 from duksis/ruby_2

Ruby 2.0.0