This means you can just do `cd tests/ && ./run-tests` to run the tests now.
You can still override the APK source with the first argument, like:
cd tests/ && ./run-tests /path/to/lots/of/apks/dir
Using `python setup.py install`, things in non-standard python paths need
to be added to the MANIFEST in order for them to be included and installed.
There might be a better solution for this, but I haven't found it.