Fix for tox failing on coverage

Coverage was failing as coverage target was deleting coverage data
before coverage html was run as a side-effect of running coverage
combine. This change fixes it.

Change-Id: I08c974724cc81423f4d440a88d704cfafb75829f

.coveragerc

@@ -0,0 +1,3 @@
+[report]
+include = syntribos/*
+omit = syntribos/tests/unit/*

tox.ini

@@ -9,10 +9,9 @@ setenv=VIRTUAL_ENV={envdir}
 deps=-r{toxinidir}/requirements.txt
      -r{toxinidir}/test-requirements.txt
 commands =
-    python setup.py testr --coverage --slowest --testr-args='{posargs}'
-    coverage combine
-    coverage report -m
     coverage erase
+    python setup.py testr --coverage --slowest  --testr-args='{posargs}'
+    coverage report -m
 
 [testenv:docs]
 commands =