dev-python/mccabe: use py.test to run tests

This way testsuite actually works on Python < 3.5
because pytest decorators are respected properly.

Package-Manager: portage-2.2.27

dev-python/mccabe/mccabe-0.4.0.ebuild

@@ -29,5 +29,5 @@ src_prepare() {
 }
 
 python_test() {
-	${EPYTHON} test_mccabe.py || die
+	py.test -v || die "Testing failed with ${EPYTHON}"
 }