Separated test dependencies from runtime dependencies

requirements.txt

-mock==1.0.1
 requests==2.2.1
 six>=1.3.0
 websocket-client==0.11.0

requirements3.txt

-mock==1.0.1
 requests==2.2.1
 six>=1.3.0
 websocket-client==0.11.0

test-requirements.txt

+mock==1.0.1
\ No newline at end of file

tox.ini

@@ -18,7 +18,9 @@ deps = -r{toxinidir}/requirements.txt
 usedevelop=True
 commands =
     {envpython} tests/test.py
-deps = -r{toxinidir}/requirements3.txt
+deps =
+    -r{toxinidir}/requirements3.txt
+    -r{toxinidir}/test-requirements.txt
 
 [testenv:flake8]
 commands = flake8 docker tests