pipenv: downgrade zipp to restore support for python3.5

https://github.com/fphammerle/ical2vdir/pull/10/checks?check_run_id=783228405#step:5:33

Pipfile

@@ -13,6 +13,9 @@ pylint = "*"
 pylint-import-requirements = "*"
 pytest = "*"
 pytest-cov = "*"
+# zipp v2.0.0 dropped support for python3.5
+# https://github.com/jaraco/zipp/commit/05a3c52b4d41690e0471a2e283cffb500dc0329a
+zipp = "<2"
 
 [requires]
 python_version = "3"

Pipfile.lock

@@ -1,7 +1,7 @@
 {
     "_meta": {
         "hash": {
-            "sha256": "b2836ed95b20b4c6750905d0a3165499e3e994493dd59f9ac5c87224929150c1"
+            "sha256": "6047dbe117241465f5f6e6a880315669eacd82765c4280c52f3977db64f04e4d"
         },
         "pipfile-spec": 6,
         "requires": {
@@ -298,10 +298,11 @@
         },
         "zipp": {
             "hashes": [
-                "sha256:aa36550ff0c0b7ef7fa639055d797116ee891440eac1a56f378e2d3179e0320b",
+                "sha256:c70410551488251b0fee67b460fb9a536af8d6f9f008ad10ac51f615b6a521b1",
-                "sha256:c599e4d75c98f6798c509911d08a22e6c021d074469042177c8c86fb92eefd96"
+                "sha256:e0d9e63797e483a30d27e09fffd308c59a700d365ec34e93cc100844168bf921"
             ],
-            "version": "==3.1.0"
+            "index": "pypi",
+            "version": "==1.2.0"
         }
     }
 }