Add AWS_REGION to heroku install

app.json

@@ -87,7 +87,7 @@
       "required": false
     },
     "AWS_ACCESS_KEY_ID": {
-      "description": "Needed to save file uploads. Optional for dev / testing.",
+      "description": "Needed to save file uploads. Optional for development / testing",
       "required": false
     },
     "AWS_SECRET_ACCESS_KEY": {
@@ -107,6 +107,11 @@
       "value": "26214400",
       "required": false
     },
+    "AWS_REGION": {
+      "value": "us-east-1",
+      "description": "Region in which the above S3 bucket exists",
+      "required": false
+    },
     "SMTP_HOST": {
       "description": "smtp.example.com (optional)",
       "required": false