Summary:
Changes the unit test comparsion to use ```ASSERT_FLOAT_EQ``` instead of ```ASSERT_EQ``` as they check float values.
Closes https://github.com/facebook/css-layout/pull/257
Reviewed By: splhack
Differential Revision: D4213809
Pulled By: emilsjolander
fbshipit-source-id: a79d310840814f26a122e1a0f6db47383b17d7e2