Convert specs to RSpec 2.99.1 syntax with Transpec

This conversion is done by Transpec 2.3.6 with the following command:
    transpec -f -c "bundle exec rake spec"

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

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

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

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

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

* 2 conversions
    from: lambda { }.should
      to: expect { }.to

* 2 conversions
    from: pending
      to: skip

For more details: https://github.com/yujinakayama/transpec#supported-conversions
Clean these up to be more readable.
Fix this to be more concise and consistent.

This was a surprisingly large amount of work.
Merge pull request #554 from apenney/unit-test-changes

Unit test changes