added npm lint script

Author: Brian Hulette

js/README.md

@@ -18,6 +18,7 @@ From this directory, run:
 
 ``` bash
 $ npm install   # pull dependencies
+$ npm run lint -- <filename>  # run tslint
 $ npm run build # build typescript (run tsc and webpack)
 $ npm run test  # run the unit tests (node.js only)
 ```

js/package.json

@@ -6,7 +6,8 @@
   "scripts": {
     "build": "./flatbuffers.sh && tsc && tsc -m es6 --outDir lib-esm && webpack",
     "clean": "rm -rf lib lib-esm _bundles",
-    "test": "./node_modules/mocha/bin/mocha ./spec/arrow.js"
+    "test": "./node_modules/mocha/bin/mocha ./spec/arrow.js",
+    "lint": "./node_modules/tslint/bin/tslint"
   },
   "author": "",
   "repository": "https://github.com/apache/arrow/",
@@ -15,6 +16,7 @@
     "awesome-typescript-loader": "^3.1.3",
     "chai": "^3.5.0",
     "mocha": "^3.3.0",
+    "tslint": "^5.3.2",
     "typescript": "^2.3.2",
     "uglifyjs-webpack-plugin": "^0.4.3",
     "webpack": "^2.3.3"