Add the ability to run tests directly

This will be useful to implement a self-test system that executes a
particular set of tests on the target device.

https://phabricator.endlessm.com/T34155

Author: dylanmccall

src/kolibri_android/tests/__main__.py

@@ -0,0 +1,18 @@
+import unittest
+from pathlib import Path
+
+
+def main():
+    this_dir = Path(__file__).parent
+
+    selftest_loader = unittest.TestLoader()
+    selftests = selftest_loader.discover(this_dir)
+
+    selftest_runner = unittest.runner.TextTestRunner()
+    selftest_runner.run(selftests)
+
+    selftest_suite = unittest.TestSuite()
+
+
+if __name__ == "__main__":
+    main()