Add test-requirements.txt

test-requirements.txt

+flake8
+bandit>=1.1.0 # Apache-2.0
+
+# Remove once we rely on coverage 4.3+
+# https://bitbucket.org/ned/coveragepy/issues/519/
+coverage!=4.4,>=4.0 # Apache-2.0
+
+stestr>=1.0.0 # Apache-2.0
+testtools>=1.4.0
+
+pytest
+pytest-cov