ignore cli and test files from test coverage to get correct coverage percentage (#361)

Author: rytilahti

tox.ini

@@ -13,7 +13,7 @@ deps=
   pytest-cov
   voluptuous
 commands=
-    py.test --cov miio
+    py.test --cov --cov-config=tox.ini miio
 
 [testenv:docs]
 basepython=python
@@ -40,3 +40,10 @@ max-line-length = 100
 [testenv:typing]
 deps=mypy
 commands=mypy --ignore-missing-imports miio
+
+[coverage:run]
+source = miio
+branch = True
+omit =
+  miio/*cli.py
+  miio/tests/*