Redislite support

[dwighthubbard]

This pull request does the following:

1. Adds support for redislite
2. Adds tox and travis configuration to implement CI to test the module against multiple python interpreters with both redis and redislite modules.
3. Removes the distutils_setup code (tox was unable to build and install the package locally with it)

[dwighthubbard]

Almost forgot, added a fix to make things work properly on python3