chore(package): update eslint to version 6.3.0

Closes #151

Author: greenkeeper[bot]

package.json

@@ -49,7 +49,7 @@
     "@types/node": "~8.9.4",
     "codecov": "^3.0.4",
     "codelyzer": "~4.5.0",
-    "eslint": "^5.16.0",
+    "eslint": "^6.3.0",
     "jasmine-core": "~2.99.1",
     "jasmine-spec-reporter": "~4.2.1",
     "karma": "~4.0.0",