Adding a tox coverage target for fm-rest-api.

As new unit tests are being added, the coverage target
helps to view their impact.

Story: 2007082
Task: 38836
Change-Id: I2d57aac7c633ab358a2d31bfc8d8a8635931527f
Signed-off-by: albailey <Al.Bailey@windriver.com>

fm-rest-api/fm/.coveragerc

@@ -0,0 +1,8 @@
+[run]
+branch = True
+source = fm
+omit = fm/tests/*
+
+[report]
+ignore_errors = True
+

fm-rest-api/fm/tox.ini

@@ -29,6 +29,16 @@ commands =
   stestr run {posargs}
   stestr slowest
 
+[testenv:cover]
+deps = {[testenv]deps}
+       coverage
+setenv = {[testenv]setenv}
+         PYTHON=coverage run --parallel-mode
 
-
-
+commands =
+   coverage erase
+   stestr run {posargs}
+   coverage combine
+   coverage html -d cover
+   coverage xml -o cover/coverage.xml
+   coverage report