Fix two small code error in examples.

examples/auth/auth.py

@@ -197,8 +197,8 @@ def build_sample_db():
 if __name__ == '__main__':
 
     # Build a sample db on the fly, if one does not exist yet.
-    app_dir = op.realpath(os.path.dirname(__file__))
-    database_path = op.join(app_dir, app.config['DATABASE_FILE'])
+    app_dir = os.path.realpath(os.path.dirname(__file__))
+    database_path = os.path.join(app_dir, app.config['DATABASE_FILE'])
     if not os.path.exists(database_path):
         build_sample_db()