Investigate using Hypothesis for some tests
Hypothesis recently added support for generating pandas objects: http://hypothesis.readthedocs.io/en/latest/numpy.html#pandas

This could be useful for testing some of the higher-level methods like `melt`, `merge`, etc.

Are there any objections to adding some hypothesis-based tests to our test suite? Is anyone familiar with hypothesis and interested in putting together examples of how we could use it?