Move tests/ into wafflehaus package

Make it easier for other wafflehaus subprojects to reuse
our tests and utils. tests/ being in the global namespace
made it impossible.

Other changes:
- Rename TestBase to TestCase for consistency
- Move TestCase to wafflehaus.tests
- Remove test_base, it's not a test
- Remove commented out code in tests/
Merge pull request #47 from mgagne/cleanup_tests

Move tests/ into wafflehaus package