Adding husky pre-commit hooks

Author: kelsonpw

package.json

@@ -38,6 +38,7 @@
     "eslint-plugin-prettier": "^3.3.0",
     "express": "^4.16.2",
     "fs-extra": "^4.0.2",
+    "husky": "^4.3.6",
     "jsdoc": "^3.6.3",
     "jsdoc-to-markdown": "^6.0.1",
     "karma": "^4.0.0",
@@ -49,6 +50,7 @@
     "karma-sauce-launcher": "^2.0.2",
     "karma-sinon": "^1.0.5",
     "karma-sourcemap-loader": "^0.3.7",
+    "lint-staged": "^10.5.3",
     "mocha": "^4.0.1",
     "prettier": "^2.2.1",
     "requirejs": "^2.3.6",
@@ -84,5 +86,15 @@
   "homepage": "https://github.com/amplitude/amplitude-javascript#readme",
   "directories": {
     "test": "test"
+  },
+  "husky": {
+    "hooks": {
+      "pre-commit": "lint-staged"
+    }
+  },
+  "lint-staged": {
+    "{src,test,scripts}/**/*.js": [
+      "yarn run fix"
+    ]
   }
 }