Remove useless way of running unittests

There is already the perfectly fine `python ./setup.py test` or `python
./setup.py nosetest` if nose is installed and tox.

The run_tests script is based on tests module importing all submodules
but this currently fails as it seems some files were not added to the
VCS in commit "implement UDS (Unix Domain Socket) sender" commit.

Author: EvaSDK

run_tests.py

@@ -1,6 +0,0 @@
-# -*- coding: utf-8 -*-
-
-from tests.test_event import *
-from tests.test_handler import *
-from tests.test_sender import *
-from tests.test_unix_domain_socket_sender import *