Add coverage job

This patch set adds in a python coverage job for pegleg using pytest.

Change-Id: Ice0332cc454f488e0372d5ab03e8b0a37db9efd1
Signed-off-by: Tin Lam <tin@irrational.io>

.zuul.yaml

@@ -14,6 +14,7 @@
     templates:
       - openstack-python35-jobs
       - openstack-python36-jobs
+      - openstack-cover-jobs
     check:
       jobs:
         - openstack-tox-pep8

tox.ini

@@ -1,5 +1,5 @@
 [tox]
-envlist = py35, py36, pep8, docs
+envlist = py35, py36, pep8, docs, cover
 minversion = 2.3.1
 # Allows docs to be built without setup.py having to exist. Requires that
 # usedevelop be False as well (which it is by default).
@@ -47,6 +47,14 @@ commands =
 basepython=python3
 commands = bandit -r pegleg -n 5
 
+[testenv:cover]
+basepython = python3
+deps =
+  -r{toxinidir}/requirements.txt
+  -r{toxinidir}/test-requirements.txt
+commands =
+  pytest --cov=pegleg --cov-report html:cover --cov-report xml:cover/coverage.xml --cov-report term --cov-fail-under 84 tests/
+
 [testenv:venv]
 commands = {posargs}