Convert specs to RSpec 2.99.2 syntax with Transpec

Please ignore previous pull request from me - I've since discovered that what I should have done was to use transpec to upgrade to Rspec 3.0.0!  Details below for the changes I made using transpec. All tests now pass with both rspec 2.99.2 and rspec 3.0.0, with no deprecation warnings.

This conversion is done by Transpec 2.3.6 with the following command:
    transpec

* 10 conversions
    from: obj.stub(:message)
      to: allow(obj).to receive(:message)

* 4 conversions
    from: be_false
      to: be_falsey

* 4 conversions
    from: be_true
      to: be_truthy

* 2 conversions
    from: Klass.any_instance.stub(:message)
      to: allow_any_instance_of(Klass).to receive(:message)

* 2 conversions
    from: expect(collection).to have(n).items
      to: expect(collection.size).to eq(n)

For more details: https://github.com/yujinakayama/transpec#supported-conversions