added pre-commit hook.

Author: Morgul

package.json

@@ -37,6 +37,20 @@
   },
   "devDependencies": {
     "eslint": "^6.0.1",
+    "husky": "^3.0.0",
+    "lint-staged": "^9.2.0",
     "mocha": "^6.1.4"
+  },
+  "husky": {
+    "hooks": {
+      "pre-commit": "lint-staged"
+    }
+  },
+  "lint-staged": {
+    "*.js": [
+      "yarn run lint",
+      "git add"
+    ]
+
   }
 }