tests: Integrated tests with setup.py

* Replaced run_tests.py with run_tests.sh

Signed-off-by: Joe MacMahon <joe.macmahon@cern.ch>
tests: Added tox.ini

Signed-off-by: Joe MacMahon <joe.macmahon@cern.ch>
docs: Updated documentation generating command in README.rst

Signed-off-by: Joe MacMahon <joe.macmahon@cern.ch>