Ensure cancellation methods return `true`.

We want to change `be_true` to `be true`,
not `be_truthy`.
Upgrade to rspec 2.99.
Convert specs to RSpec 2.99.0.beta2 syntax with Transpec

This conversion is done by Transpec 1.10.3 with the following command:
    transpec --boolean-matcher true,false

* 14 conversions
    from: obj.should_receive(:message)
      to: expect(obj).to receive(:message)

* 13 conversions
    from: be_true
      to: be true

* 12 conversions
    from: expect(collection).to have(n).items
      to: expect(collection.size).to eq(n)

* 11 conversions
    from: obj.stub(:message)
      to: allow(obj).to receive(:message)

* 7 conversions
    from: be_false
      to: be false

* 6 conversions
    from: expect(obj).to have(n).entries
      to: expect(obj.entries.size).to eq(n)

* 3 conversions
    from: obj.should_not_receive(:message)
      to: expect(obj).not_to receive(:message)

* 3 conversions
    from: expect(obj).to have_at_most(n).entries
      to: expect(obj.entries.size).to be <= n

* 1 conversion
    from: expect(obj).to have_at_least(n).job_jids
      to: expect(obj.job_jids.size).to be >= n

* 1 conversion
    from: Klass.any_instance.stub(:message)
      to: allow_any_instance_of(Klass).to receive(:message)
Upgrade to rspec 3.
Convert specs to RSpec 3.0.0.beta2 syntax with Transpec

This conversion is done by Transpec 1.10.3 with the following command:
    transpec --boolean-matcher true,false

* 8 conversions
    from: obj.stub(:message => value)
      to: allow(obj).to receive_messages(:message => value)

* 2 conversions
    from: failure_message_for_should { }
      to: failure_message { }

* 1 conversion
    from: match_for_should { }
      to: match { }

* 1 conversion
    from: failure_message_for_should_not { }
      to: failure_message_when_negated { }

* 1 conversion
    from: match_for_should_not { }
      to: match_when_negated { }
Update to recommended rspec 3 settings.

There is still some work to be done for a few things.
Verify partial doubles.
Disable rspec monkey patching.
Remove spec_helper requires.

It's no longer needed now that we have it in .rspec.
Verify doubled constant names.
Merge pull request #66 from seomoz/upgrade-to-rspec-3

Upgrade to rspec 3