Use rspec2 instead of legacy rspec

All tests pass, but with deprecated methods.
Deprecated function in rspec2: stub!

Replaced by stub
Deprecated methods in rspec2: mock

Replaced by double
All tests run cleanly
Add .bundle to .gitignore

As per http://bundler.io/v1.3/rationale.htm this is automated configuration files which should not be under version control.
Update the bundle dependencies to include rspec 2

This update was done running bundle update to update all dependencies. All tests pass.

Gemfile.lock add's hard dependency versions to this gem. 
It was forcing rspec down to 1.2.6.

This reference (http://bundler.io/v1.3/rationale.html) seems to say that you should check it into versioning, but then it would be good to explain somewhere in development docs that you need to regenerate Gemfile.lock with 'bundle update' before pushing and that you should test if things work with bundle install. I just completely bypassed bundle causing this version conflict.

See also this, which seems to claim it's a bad idea to put Gemfile.lock in version control: 
http://yehudakatz.com/2010/12/16/clarifying-the-roles-of-the-gemspec-and-gemfile/

A good explanation can also be found in "man bundle install", especially the section on deployment mode.
Try to work around travis bug travis-ci/travis-ci#2220

Not sure if it'll work but it's worth to try
Merge pull request #4 from najamelan/feature/rspec2

Update rspec to rspec2