Update through2 to version 3.0.0 (#48)

Author: greenkeeper[bot]

package.json

@@ -32,7 +32,7 @@
     "lesshint-reporter-stylish": "^3.0.0",
     "minimatch": "^3.0.4",
     "plugin-error": "^1.0.0",
-    "through2": "^2.0.0"
+    "through2": "^3.0.0"
   },
   "devDependencies": {
     "eslint": "^5.0.0",