Install gunicorn via Pipenv

.platform.app.yaml

@@ -12,7 +12,6 @@ type: 'python:3.7'
 # The build-time dependencies of the app.
 dependencies:
     python:
-       gunicorn: '*'
        pipenv: '*'
 
 # The relationships of the application with services or other applications.

Pipfile

@@ -6,6 +6,7 @@ name = "pypi"
 [packages]
 django = ">=2.1.2,<3.0"
 "psycopg2-binary" = "*"
+gunicorn = "*"
 
 [requires]
 python_version = "3.7"

Pipfile.lock

 {
     "_meta": {
         "hash": {
-            "sha256": "2aeaa41d7d67c34f9c0ece7bbcee99d8932c5011531d00eed287e0e41f53098d"
+            "sha256": "d4994e064025e5b73e75daa89b5385635c2a6b312dfc78ee87c59e138b2cb8b6"
         },
         "pipfile-spec": 6,
         "requires": {
@@ -24,6 +24,14 @@
             "index": "pypi",
             "version": "==2.1.2"
         },
+        "gunicorn": {
+            "hashes": [
+                "sha256:aa8e0b40b4157b36a5df5e599f45c9c76d6af43845ba3b3b0efe2c70473c2471",
+                "sha256:fa2662097c66f920f53f70621c6c58ca4a3c4d3434205e608e121b5b3b71f4f3"
+            ],
+            "index": "pypi",
+            "version": "==19.9.0"
+        },
         "psycopg2-binary": {
             "hashes": [
                 "sha256:04afb59bbbd2eab3148e6816beddc74348078b8c02a1113ea7f7822f5be4afe3",
@@ -62,10 +70,10 @@
         },
         "pytz": {
             "hashes": [
-                "sha256:a061aa0a9e06881eb8b3b2b43f05b9439d6583c206d0a6c340ff72a7b6669053",
-                "sha256:ffb9ef1de172603304d9d2819af6f5ece76f2e85ec10692a524dd876e72bf277"
+                "sha256:642253af8eae734d1509fc6ac9c1aee5e5b69d76392660889979b9870610a46b",
+                "sha256:91e3ccf2c344ffaa6defba1ce7f38f97026943f675b7703f44789768e4cb0ece"
             ],
-            "version": "==2018.5"
+            "version": "==2018.6"
         }
     },
     "develop": {}