Move RandomModule class to its own module. random.py
Maintenence on Random class.

* Rename the class RandomModule -> Random
* Add docstrings mostly from NumPy.
* pep8
* fixbugs from old api changes
Add random import to __init__.py
Add tests for random.py

These tests are pretty dumb, they only check that we are getting the
correct shapes returned.
Remove RandomModule from client.py
Merge pull request #134 from cowlicks/move-random

Move `RandomModule` to its own module. Do maintenance on it.