remove some unused dependencies

site/package.json

@@ -22,23 +22,10 @@
     "jsonwebtoken": "^8.5.1",
     "marked": "^3.0.5",
     "pg": "^8.7.1",
-    "polka": "^1.0.0-next.9",
     "prism-svelte": "^0.4.3",
-    "prismjs": "^1.25.0",
-    "sirv": "^1.0.0",
-    "yootils": "0.0.16"
+    "prismjs": "^1.25.0"
   },
   "devDependencies": {
-    "@babel/core": "^7.6.0",
-    "@babel/plugin-syntax-dynamic-import": "^7.2.0",
-    "@babel/plugin-transform-runtime": "^7.6.0",
-    "@babel/preset-env": "^7.6.0",
-    "@babel/runtime": "^7.6.0",
-    "@rollup/plugin-babel": "^5.0.0",
-    "@rollup/plugin-commonjs": "^17.0.0",
-    "@rollup/plugin-json": "^4.1.0",
-    "@rollup/plugin-node-resolve": "^11.0.0",
-    "@rollup/plugin-replace": "^2.2.0",
     "@sindresorhus/slugify": "^0.9.1",
     "@sveltejs/adapter-node": "next",
     "@sveltejs/kit": "next",
@@ -46,14 +33,10 @@
     "@sveltejs/svelte-repl": "^0.3.0",
     "degit": "^2.1.4",
     "dotenv": "^10.0.0",
-    "esm": "^3.2.25",
     "jimp": "^0.8.0",
     "mocha": "^6.2.0",
     "node-fetch": "^2.6.1",
     "node-pg-migrate": "^6.0.0",
-    "rollup": "^2.30.0",
-    "rollup-plugin-svelte": "^7.0.0",
-    "rollup-plugin-terser": "^7.0.0",
     "shelljs": "^0.8.3",
     "svelte": "^3.39.0"
   },