Pull edx-username-changer as this is deprecated

Author: jkachel

repos_info.json

@@ -168,14 +168,6 @@
       "packaging_tool": "npm",
       "versioning_strategy": "npm"
     },
-    {
-      "name": "edx-username-changer",
-      "repo_url": "https://github.com/mitodl/edx-username-changer.git",
-      "channel_name": "doof-edx-username-changer",
-      "project_type": "library",
-      "packaging_tool": "setuptools",
-      "versioning_strategy": "python"
-    },
     {
       "name": "mitxonline",
       "repo_url": "https://github.com/mitodl/mitxonline.git",