Add openpilot tests

selfdrive/test/cpp_harness.py

@@ -0,0 +1,11 @@
+#!/usr/bin/env python3
+import subprocess
+import sys
+
+from openpilot.common.prefix import OpenpilotPrefix
+
+
+with OpenpilotPrefix():
+  ret = subprocess.call(sys.argv[1:])
+
+exit(ret)