Add self tests for gyp_to_android.

tools/tests/run_all.py

 #!/usr/bin/python
 
 """
 Copyright 2013 Google Inc.
 
 Use of this source code is governed by a BSD-style license that can be
 found in the LICENSE file.
 
 Run all self-tests that were written in Python, raising an exception if any
 of them fail.
 """
 
 import render_pictures_test
 import skimage_self_test
+import gyp_to_android_tests
 
 def main():
   """Run all self-tests, raising an exception if any of them fail."""
   render_pictures_test.main()
   skimage_self_test.main()
+  gyp_to_android_tests.main()
 
 if __name__ == '__main__':
   main()