Lock RSpec version to 2.14.

When starting development with the guard-jasmine gem,
the tests are failing because RSpec 3 gets installed, and the old RSpec
syntax (should, stub, etc) is being used in the tests.

This commit locks RSpec to 2.14 and can be removed whenever the upgrade
to RSpec 3 happens.
Merge pull request #168 from gonzedge/lock-rspec

Lock RSpec version to 2.14