chore(package): update eslint to version 6.5.1

Closes #48

Author: greenkeeper[bot]

package.json

@@ -10,7 +10,7 @@
   "description": "makes IE capable of rendering several of the most useful CSS3 decoration features.",
   "devDependencies": {
     "codecov": "^3.0.2",
-    "eslint": "^5.0.0",
+    "eslint": "^6.5.1",
     "got": "^9.0.0",
     "mocha": "^5.2.0",
     "nyc": "^12.0.2",