dev env: add zipp to fix pipeline on python3.7

Pipfile

@@ -15,6 +15,11 @@ pytest-cov = "*"
 # > File "[...]/python3.7/site-packages/_pytest/compat.py", line 56, in <module>
 # >  import importlib_metadata  # noqa: F401
 importlib-metadata = {markers = "python_version < '3.8'"}
+# > File "[...]/python3.7/site-packages/importlib_metadata/__init__.py", line 6, in <module>
+# >  import zipp
+zipp = {markers = "python_version < '3.8'"}
 
 [requires]
 python_version = "3"
+
+# Pipfile syntax: https://github.com/pypa/pipfile#pipfile

Pipfile.lock

@@ -1,7 +1,7 @@
 {
     "_meta": {
         "hash": {
-            "sha256": "f10a7bd1df36e44578a3fd1f3ad1a4f9ce6ab09f97598927dc56d096073682e1"
+            "sha256": "f03f840e841fb84742c81c5058cbdc3ce6df5331cd219ff14426f5299fa90291"
         },
         "pipfile-spec": 6,
         "requires": {
@@ -317,6 +317,14 @@
             ],
             "markers": "python_version >= '2.7' and python_version not in '3.0, 3.1, 3.2, 3.3, 3.4'",
             "version": "==1.13.3"
+        },
+        "zipp": {
+            "hashes": [
+                "sha256:9f50f446828eb9d45b267433fd3e9da8d801f614129124863f9c51ebceafb87d",
+                "sha256:b47250dd24f92b7dd6a0a8fc5244da14608f3ca90a5efcd37a3b1642fac9a375"
+            ],
+            "markers": "python_version < '3.8'",
+            "version": "==3.7.0"
         }
     }
 }