Decode subprocess output to handle Python 3 in readmegen (GoogleCloudPlatform#1370)

Author: andrewsg

scripts/readme-gen/readme_gen.py

@@ -34,7 +34,7 @@
 
 
 def get_help(file):
-    return subprocess.check_output(['python', file, '--help'])
+    return subprocess.check_output(['python', file, '--help']).decode()
 
 
 def main():