use __file__ so that we can copy/paste the code.

examples/tests/test_logistic_regression.py

@@ -99,4 +99,4 @@ class test_logistic_regression_example(unittest.TestCase):
 
 if __name__ == '__main__':
     from theano.tests import main
-    main("test_logistic_regression")
+    main(__file__)

examples/tests/test_wiki.py

@@ -310,4 +310,4 @@ class T_test_wiki_module(unittest.TestCase):
 
 if __name__ == '__main__':
     from theano.tests import main
-    main("test_wiki")
+    main(__file__)