Updated old syntax to the newest style

Some of the entries were using the old syntax. Though that would still
work, it will be deprecated in a later release of RSpec, so it should
not be used for new development.

Some changes include:
 - mock to double
 - .should to expect()
 - mock_model to double
 - .stub to allow()
Merge pull request #2 from reachlocal/update_syntax

Updated old syntax entries to the newest style