Add git migration tags for um, um_docs, and socrates (#130)

Author: yaswant

git-migration/config.json

@@ -53,7 +53,8 @@
         { "vn1.2": 10378 },
         { "vn1.3": 10614 },
         { "vn1.4": 11231 },
-        { "vn1.5": 11589 }
+        { "vn1.5": 11589 },
+        { "git_migration": 12145 }
       ]
     },
     {
@@ -391,7 +392,8 @@
         { "vn13.6": 125228 },
         { "vn13.7": 127063 },
         { "vn13.8": 128862 },
-        { "vn13.9": 130315 }
+        { "vn13.9": 130315 },
+        { "git_migration": 131672 }
       ]
     },
     {
@@ -445,7 +447,8 @@
         { "vn13.6": 124981 },
         { "vn13.7": 127030 },
         { "vn13.8": 128625 },
-        { "vn13.9": 130128 }
+        { "vn13.9": 130128 },
+        { "git_migration": 131675 }
       ]
     },
     {