chore(package): update less-loader to version 6.1.0

Closes #34

Author: greenkeeper[bot]

package.json

@@ -68,7 +68,7 @@
     "husky": "^3.1.0",
     "jest": "^24.9.0",
     "less": "^3.10.3",
-    "less-loader": "^5.0.0",
+    "less-loader": "^6.1.0",
     "lint-staged": "^9.5.0",
     "mini-css-extract-plugin": "^0.9.0",
     "postcss-import": "^12.0.1",