Add sure to list of Testing Frameworks

Created by: timofurrer

sure is an awesome testing library which provides powerful and flexible assertions.

This library is awesome because it monkey-patches all python objects with methods like should or when or to:

import sure

(2 + 2).should.be.equal(4)
(3.4 + 4).should.eql(7.5)

{'foo': 'bar'}.should.equal({'foo': 'bar'})
{'foo': 'bar'}.should.have.key('foo').which.should.equal('bar')

step.run.when.called_with(some_id=1).should.return_value(Step.PASSED)

It makes it really easy to use and the the test cases are super readable and maintainable.