chore(package): update eslint to version 5.15.1

Closes #122

Author: greenkeeper[bot]

package.json

@@ -47,7 +47,7 @@
     "babel-plugin-transform-runtime": "^6.23.0",
     "babel-preset-env": "^1.6.1",
     "babel-register": "^6.26.0",
-    "eslint": "^4.19.1",
+    "eslint": "^5.15.1",
     "eslint-plugin-babel": "^5.1.0",
     "eslint-plugin-markdown": "^1.0.0-beta.6",
     "jasmine": "^3.1.0",