Convert tests to TypeScript

Still broken

Author: pirelenito

package.json

@@ -27,7 +27,7 @@
   "scripts": {
     "start": "tsdx watch",
     "build": "tsdx build",
-    "test": "tsdx test",
+    "test": "tsdx test --env=node",
     "lint": "tsdx lint"
   },
   "peerDependencies": {},
@@ -43,11 +43,13 @@
     "trailingComma": "all"
   },
   "devDependencies": {
+    "@types/fs-extra": "^8.0.0",
     "@types/jest": "^24.0.18",
     "@types/webpack": "^4.39.2",
     "husky": "^3.0.8",
     "tsdx": "^0.9.3",
     "tslib": "^1.10.0",
-    "typescript": "^3.6.3"
+    "typescript": "^3.6.3",
+    "webpack": "^4.41.0"
   }
 }