Add tox in test-requirements.txt file
Add tox in test-requirements.txt file

Change-Id: Ia94e2e42daa8f02918da4560c33b9c775d920dc9

redhat-cip/dci-control-server,enovance/dci-control-server,enovance/dci-control-server,redhat-cip/dci-control-server