Allow `assertEqual` to allow different number types

[markwpearce]

Normally, you don't really care if a value is a float vs. an integer

so m.assertEqual(70.0, 70) should not fail a test

[TwitchBronBron]

@chrisdp you've done a lot of work on the tests lately. Thoughts on this? (Or an alternative assertion function)

[chrisdp]

I personally like the idea but worry about breaking existing tests. I was thinking we would tackle some of this with a new set of expects or asserts.