chore(package): update eslint to version 6.7.1

Closes #52

Author: greenkeeper[bot]

package.json

@@ -54,7 +54,7 @@
   "devDependencies": {
     "@commitlint/cli": "^7.1.2",
     "@commitlint/config-conventional": "^7.1.2",
-    "eslint": "^5.6.0",
+    "eslint": "^6.7.1",
     "eslint-config-prettier": "^3.1.0",
     "eslint-config-standard": "^12.0.0",
     "eslint-formatter-pretty": "^1.3.0",