Merge pull request googleapis#495 from dhermes/require-100-cover

Require 100% line coverage for tests.

Author: dhermes

tox.ini

@@ -84,7 +84,7 @@ deps = {[testenv]basedeps}
 basepython = {[coverbase]basepython}
 commands =
     {[coverbase]commands}
-    coverage report --show-missing --fail-under 80
+    coverage report --show-missing --cover-min-percentage=100
 deps =
     {[coverbase]deps}