Add eslint and make it happy.

.eslintrc.js

@@ -0,0 +1,6 @@
+module.exports = {
+  root: true,
+  extends: [
+    'standard'
+  ]
+}

index.js

@@ -25,7 +25,7 @@ Commands:
 }
 
 // The main CLI.
-const main = module.exports = (config) => {
+module.exports = (config) => {
   return expandConfig(config).then(config => {
     const args = process.argv.slice(2)
 
@@ -197,8 +197,6 @@ const download = module.exports.download = (src, writer) => {
       }
     }
 
-    const contentType = res.headers['content-type']
-
     return resolve(new Promise((resolve, reject) => {
       const decode = (stream) => {
         const contentEncoding = res.headers['content-encoding']
@@ -393,7 +391,6 @@ const expandConfig = module.exports.expandConfig = (options) => {
 
     const context = options.context || path.resolve(__dirname, '../..')
     const pkg = require(path.resolve(context, 'package'))
-    const repoUrl = repositoryUrlFromPackage(pkg)
 
     const bindings = options.bindings.map(binding => {
       const name = binding.name

package.json

@@ -13,5 +13,11 @@
     "type": "git",
     "url": "https://github.com/sorccu/node-prebuilt-bindings.git"
   },
-  "main": "./index"
+  "main": "./index",
+  "devDependencies": {
+    "eslint": "^3.9.1",
+    "eslint-config-standard": "^6.2.1",
+    "eslint-plugin-promise": "^3.3.0",
+    "eslint-plugin-standard": "^2.0.1"
+  }
 }