Separate example and tests

Each folder has is own settings and urls and can be tested with
`runtests.py`

1. `./runtests` run tests with `tests/settings.py` file
2. `./runtests example` run tests with `example/settings.py` file

`runtests.py` write to stdout the settings file used.
Merge pull request #32 from benjaminabel/separate-test-and-example

Separate example and tests