Add subpackage to setup

Author: hermansje

setup.py

@@ -30,7 +30,7 @@
 setup(
     name=PACKAGE_NAME,
     version=VERSION,
-    packages=[PACKAGE_NAME, "pythonwhat.test_funcs"],
+    packages=[PACKAGE_NAME, "pythonwhat.checks", "pythonwhat.test_funcs"],
     install_requires=REQUIREMENTS,
     description="Submission correctness tests for Python",
     long_description=README,