Equals puts values around the wrong way

[Jonathan Lange]

A test that does this:

    self.assertThat('a', Equals('b'))

Will report an error that looks like this:

    testtools.matchers._impl.MismatchError: 'b' != 'a'

I would expect it to look like this instead:

    testtools.matchers._impl.MismatchError: 'a' != 'b'

Where the order of values in the error matches the order of values on the line of the assertion. This is particularly confusing when 'a' and 'b' are variables instead of literals, and when the values are very similar (e.g. both short strings but one ends with a newline—which is expected and which is actual?)

[Jonathan Lange (jml)]

https://github.com/testing-cabal/testtools/commit/4febe2e751454131515ef5eed94fcd958c4fbfb1