fix(package.json): adds back lint script

Author: saneef

package.json

@@ -9,6 +9,7 @@
     "url": "git+https://github.com:saneef/eleventy-plugin-git-commit-date.git"
   },
   "scripts": {
+    "lint": "eslint src/**.js tests/**.js",
     "test": "ava"
   },
   "keywords": [