Ensure RSpec version greater than 2.14
Remove Gemfile.lock from the infinity_test gem.

You can see more details here:

http://yehudakatz.com/2010/12/16/clarifying-the-roles-of-the-gemspec-and-gemfile/
Move the receive expectation to the new RSpec syntax
Ensure the new RSpec syntax in all specs
Add the new RSpec expect syntax to all all shared examples in lib