Move fs-extra and path-to-regexp to dependencies

The two packages will not be installed in the correct version unless we 
specify the two packages as dependencies. This is what the 
serverless-next.js package does as well, so it is probably okay.

Author: FinnWoelm

package-lock.json

@@ -21,11 +21,10 @@
   "homepage": "https://github.com/FinnWoelm/next-on-netlify",
   "author": "Finn Woelm",
   "license": "MIT",
-  "devDependencies": {
+  "devDependencies": {},
+  "dependencies": {
     "fs-extra": "^8.1.0",
+    "next-aws-lambda": "^2.3.4",
     "path-to-regexp": "^3.2.0"
-  },
-  "dependencies": {
-    "next-aws-lambda": "^2.3.4"
   }
 }