Fix typo in README

... with a drive by improvement to boot.
Merge pull request #7 from tjarratt/patch-1

Fix typo in README
Add transpec as a development dependency

Useful for rewriting your tests to use newer rspec syntax
Convert specs to RSpec 2.14.8 syntax with Transpec

HEY DOG I HEARD YOU LIKED AST TRANSFORMS SO I REWROTE YOUR TESTS WITH
A RUBY AST PARSER.

This conversion is done by Transpec 2.0.0 with the following command:
    transpec

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

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

See also: https://github.com/yujinakayama/transpec#supported-conversions