chore(package): update eslint-config-airbnb to version 15.0.2

Closes #12

Author: greenkeeper[bot]

package.json

@@ -18,7 +18,7 @@
     "babel-preset-env": "^1.3.3",
     "coveralls": "^2.11.15",
     "eslint": "^3.15.0",
-    "eslint-config-airbnb": "^14.1.0",
+    "eslint-config-airbnb": "^15.0.2",
     "eslint-plugin-import": "^2.2.0",
     "eslint-plugin-jsx-a11y": "^3.0.2 || ^4.0.0",
     "eslint-plugin-react": "^6.9.0",