Fix travis testing (include eslint)

.eslintrc.yml

@@ -1,6 +1,8 @@
+parser: babel-eslint
 extends: airbnb-base
 rules:
   no-underscore-dangle: 0
   no-void: 0
 plugins:
   - ava
+  - import

.travis.yml

@@ -2,3 +2,6 @@ language: node_js
 after_success: npm run coverage
 node_js:
   - "8.4.0"
+script:
+- npm run lint
+- npm test

package.json

@@ -64,7 +64,7 @@
   "scripts": {
     "build": "webpack --config webpack.config.js",
     "prepublish": "npm run build",
-    "lint": "eslint ./src --fix",
+    "lint": "eslint ./src",
     "testem": "testem",
     "test": "eslint ./src & nyc --reporter=html --reporter=text ava",
     "coverage": "nyc report --reporter=text-lcov | coveralls",