Fixed indentation (PEP-8), added module docstring
In ``heatmap.heatmap`` Module:
 - Fixed right margin, added missing instance attributes in constructor, updated naming convention, et. al. (working toward full PEP-8 compliance)
 - Added module docstring with stuff I think is needed
 - Reformatted docstrings from *undefined* to *reStructuredText* / Sphinx-compatible syntax
 - Added partial docs on exceptions raised

 In ``test.tests`` Module:
 - Added TODOs I felt was missing
 - Replaced some ``self.assertTrue(isinstance(obj, cls))`` statements with, the more straight-forward, ``self.assertIsInstance(obj, cls)``
 - PEP-8 updates (fixed spacing between operators and module-level classes, respectively)
 - Added tests for RGB color values, e.g. ``self.assertIn(red, range(256))``

In ``examples.google-earth`` Module:
 - Fixed right margin (PEP-8)