Make our json output prettier.

Add an indent=2 so these files are human readable.

Change-Id: Ie75c3a85e9c9dc890c4e138e9453bf055cd265a7

docker/docker-puppet.py

@@ -382,7 +382,7 @@ for infile in infiles:
     outfile = os.path.join(os.path.dirname(infile), "hashed-" + os.path.basename(infile))
     with open(outfile, 'w') as out_f:
         os.chmod(out_f.name, 0600)
-        json.dump(infile_data, out_f)
+        json.dump(infile_data, out_f, indent=2)
 
 if not success:
     sys.exit(1)