Upgrade `all-contributors-cli`.

package.json

@@ -23,7 +23,7 @@
   "license": "(OFL-1.1 AND MIT)",
   "dependencies": {},
   "devDependencies": {
-    "all-contributors-cli": "^4.11.2",
+    "all-contributors-cli": "^6.1.1",
     "less": "^2.7.3",
     "less-plugin-clean-css": "^1.5.1",
     "svgo": "^1.1.1"