pipenv: downgrade zipp to restore compatibility with python3.5

Pipfile

@@ -16,6 +16,9 @@ pytest = "<5"
 pytest-cov = "<3,>=2"
 pytest-timeout = "<2"
 yapf = "*"
+# v2.0.0 dropped python<3.6 support
+# https://github.com/jaraco/zipp/commit/05a3c52b4d41690e0471a2e283cffb500dc0329a
+zipp = "<2"
 
 [requires]
 python_version = "3"

Pipfile.lock

@@ -1,7 +1,7 @@
 {
     "_meta": {
         "hash": {
-            "sha256": "887083d56b0181f0c91a4a797c8d73595ac931841d04af70fd435f18133f1bf5"
+            "sha256": "f30f0d1204c23c90ad891593d8213ef0cd35fd90b574408aab7624f3cc1ee357"
         },
         "pipfile-spec": 6,
         "requires": {
@@ -334,10 +334,11 @@
         },
         "zipp": {
             "hashes": [
-                "sha256:aa36550ff0c0b7ef7fa639055d797116ee891440eac1a56f378e2d3179e0320b",
-                "sha256:c599e4d75c98f6798c509911d08a22e6c021d074469042177c8c86fb92eefd96"
+                "sha256:c70410551488251b0fee67b460fb9a536af8d6f9f008ad10ac51f615b6a521b1",
+                "sha256:e0d9e63797e483a30d27e09fffd308c59a700d365ec34e93cc100844168bf921"
             ],
-            "version": "==3.1.0"
+            "index": "pypi",
+            "version": "==1.2.0"
         }
     }
 }