Add mojo/tools/mopy with paths and version utilities

mojo/tools/mopy/mojo_python_tests_runner.py

Index: mojo/tools/mopy/mojo_python_tests_runner.py
diff --git a/mojo/tools/pylib/mojo_python_tests_runner.py b/mojo/tools/mopy/mojo_python_tests_runner.py
similarity index 84%
copy from mojo/tools/pylib/mojo_python_tests_runner.py
copy to mojo/tools/mopy/mojo_python_tests_runner.py
index 3d52f1df5abf9a16dd4bb51ebbb910f06e581993..ef9a6b2b318b07fe438a8bea7ceddb3ed3430e1c 100644
--- a/mojo/tools/pylib/mojo_python_tests_runner.py
+++ b/mojo/tools/mopy/mojo_python_tests_runner.py
@@ -7,6 +7,8 @@ import os
 import sys
 import unittest
 
+import mopy.paths
+
 
 class MojoPythonTestRunner(object):
   """Helper class to run python tests on the bots."""
@@ -23,15 +25,11 @@ class MojoPythonTestRunner(object):
     args = parser.parse_args()
     self.apply_customization(args)
 
-    root_src_dir = os.path.join(os.path.dirname(__file__),
-                                os.pardir,
-                                os.pardir,
-                                os.pardir)
-
     loader = unittest.loader.TestLoader()
     print "Running Python unit tests under %s..." % self._test_dir
 
-    pylib_dir = os.path.abspath(os.path.join(root_src_dir, self._test_dir))
+    src_root = mopy.paths.Paths().src_root
+    pylib_dir = os.path.abspath(os.path.join(src_root, self._test_dir))
     if args.tests:
       if pylib_dir not in sys.path:
         sys.path.append(pylib_dir)