Issue 3754 - Initial setup of the python-abp repo.

README.md

 # python-abp
 
-A library for working with Adblock Plus filterlists.

[Sebastian Noack, 2016/03/16 00:18:41]

Perhaps you should mention tox here, maybe add a section about testing.

[Vasily Kuznetsov, 2016/03/16 13:47:14]

I was thinking that later this kind of information would go into something like
HACKING.md. But at this point, it's probably not worth creating a separate file
for it and it could already be put here. Since I'm not giving full contributor
guidelines at the moment, the section will be called "Testing".

+A library for working with Adblock Plus filter lists
+
+## Testing
+
+Unit tests for `python-abp` are located in the `/tests` directory. 
+[Pytest](http://pytest.org/) is used for quickly running the tests
+during development.
+[Tox](https://tox.readthedocs.org/) is used for testing in different
+environments (Python 2.7, Python 3.5 and PyPy) and code quality
+reporting.
+
+In order to execute the tests, first create and activate development
+virtualenv:
+
+    $ python setup.py devenv
+    $ . devenv/bin/activate
+
+With the development virtualenv activated use pytest for a quick test run:
+
+    (devenv) $ py.test tests
+
+and tox for a comprehensive report:
+
+    (devenv) $ tox