update lock file

Pipfile.lock

@@ -730,7 +730,7 @@
                 "sha256:fa2ba70284fa42c2a5ecb35e322e68823288a4251f9ba9cc77be04ae15eada68",
                 "sha256:fba85b6cd9c39be262fcd23865652920832b61583de2a2ca907dbd8e8a8c81e5"
             ],
-            "markers": "python_version >= '3.5'",
+            "markers": "python_version > '2.7'",
             "version": "==6.1"
         },
         "tqdm": {