chore(package): update eslint to version 6.3.0

Closes #233

Author: greenkeeper[bot]

package.json

@@ -26,7 +26,7 @@
     "@typescript-eslint/parser": "^1.4.2",
     "babel-eslint": "10.0.1",
     "coveralls": "^3.0.3",
-    "eslint": "^5.16.0",
+    "eslint": "^6.3.0",
     "eslint-config-airbnb": "15.1.0",
     "eslint-plugin-import": "^2.0.0",
     "eslint-plugin-jsx-a11y": "^5.1.1",