heroku post build (#603)

Author: chriswedgwood

theme/static_src/package.json

@@ -7,7 +7,8 @@
     "build": "npm run build:clean && npm run build:tailwind",
     "build:clean": "rimraf ../static/css/dist",
     "build:tailwind": "cross-env NODE_ENV=production postcss ./src/styles.css -o ../static/css/dist/styles.css --minify",
-    "dev": "cross-env NODE_ENV=development postcss ./src/styles.css -o ../static/css/dist/styles.css --watch"
+    "dev": "cross-env NODE_ENV=development postcss ./src/styles.css -o ../static/css/dist/styles.css --watch",
+    "heroku-postbuild": "npm run build"
   },
   "keywords": [],
   "author": "",