Convert specs to RSpec 2.99.1 syntax with Transpec

This conversion is done by Transpec 2.3.8 with the following command:
    transpec

* 106 conversions
    from: obj.should
      to: expect(obj).to

* 50 conversions
    from: it { should ... }
      to: it { is_expected.to ... }

* 20 conversions
    from: == expected
      to: eq(expected)

* 11 conversions
    from: it { should_not ... }
      to: it { is_expected.not_to ... }

* 10 conversions
    from: describe 'some model' { }
      to: describe 'some model', :type => :model { }

* 4 conversions
    from: describe 'some helper' { }
      to: describe 'some helper', :type => :helper { }

* 3 conversions
    from: describe 'some controller' { }
      to: describe 'some controller', :type => :controller { }

* 2 conversions
    from: obj.should_not
      to: expect(obj).not_to

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

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

For more details: https://github.com/yujinakayama/transpec#supported-conversions
Convert `stub` usage to use `allow`.
Update rspec-rails dependency.
Restore `FactoryGirl.stub` call that was converted by mistake.
Merge pull request #92 from lucasmazza/lm-bump-rspec

Update RSpec dependency.