Merge pull request #19 from kennknowles/master

Fix minor typo in docs
Better reporting for rejected properties.

This helps with #20 and #15. As for the latter, I still don't know whether to provide special handling for assertion-based tests or not.
Forces string tests to return Bool.
Adds a warning on the expectations of properties.
Merge.
Bumps to 0.3.3
Makes sure Bytes are Integral (Fixes #21).
Bumps to 0.3.4
Actually provides tests for #21