servo: Merge #7933 - Replace libpng and stb_image with PistonDevelopers/image (from mbrubeck:piston-image); r=glennw

Fixes #3368. r? @glennw

Source-Repo: https://github.com/servo/servo
Source-Revision: 0f597d389052500d9b76b9f9f89e873e6f809ab1

servo/python/tidy.py

@@ -149,7 +149,9 @@ def check_lock(file_name, contents):
     contents = contents.splitlines(True)
     idx = 1
     packages = {}
-    exceptions = ["glutin", "wayland-kbd"]      # package names to be neglected (as named by cargo)
+
+    # package names to be neglected (as named by cargo)
+    exceptions = ["glutin", "wayland-kbd"]
 
     while idx < len(contents):
         content = contents[idx].strip()