Update devDependencies to fix linting errors

Author: piranna

package.json

@@ -53,13 +53,14 @@
     "simple-get": "^3.0.3"
   },
   "devDependencies": {
-    "@types/node": "^10.12.18",
+    "@types/node": "^14.11.10",
     "assert-rejects": "^1.0.0",
-    "dtslint": "^0.5.3",
+    "dtslint": "^4.0.4",
     "express": "^4.16.3",
     "mocha": "^5.2.0",
     "pixelmatch": "^4.0.2",
-    "standard": "^12.0.1"
+    "standard": "^12.0.1",
+    "typescript": "^4.0.3"
   },
   "engines": {
     "node": ">=6"