add husky and lint-staged

package.json

@@ -22,6 +22,16 @@
     "fetch-examples-ml5:prod": "cross-env NODE_ENV=production node ./dist/fetch-examples-ml5.bundle.js",
     "heroku-postbuild": "touch .env; npm run build"
   },
+  "husky": {
+    "hooks": {
+      "pre-commit": "lint-staged"
+    }
+  },
+  "lint-staged": {
+    "*.{js,jsx}": [
+      "npm run lint-fix"
+    ]
+  },
   "jest": {
     "setupFiles": [
       "<rootDir>/jest.setup.js"
@@ -127,11 +137,13 @@
     "express-session": "^1.17.0",
     "friendly-words": "^1.1.10",
     "htmlhint": "^0.10.1",
+    "husky": "^4.2.5",
     "is-url": "^1.2.4",
     "jest-express": "^1.11.0",
     "js-beautify": "^1.10.3",
     "jsdom": "^9.8.3",
     "jshint": "^2.11.0",
+    "lint-staged": "^10.1.3",
     "lodash": "^4.17.15",
     "loop-protect": "github:catarak/loop-protect",
     "mime-types": "^2.1.26",