Add libvips heroku buildpack

app.json

@@ -107,5 +107,13 @@
     },
     "addons": [
         "heroku-postgresql"
+    ],
+    "buildpacks": [
+        {
+            "url": "https://github.com/alex88/heroku-buildpack-vips"
+        },
+        {
+            "url": "https://github.com/heroku/heroku-buildpack-nodejs"
+        }
     ]
 }