chore(package): update less to version 3.6.0

Closes #68

Author: greenkeeper[bot]

package.json

@@ -83,7 +83,7 @@
     "karma-sauce-launcher": "^1.1.0",
     "karma-spec-reporter": "0.0.31",
     "karma-webpack": "^2.0.2",
-    "less": "^2.7.2",
+    "less": "^3.6.0",
     "less-loader": "^4.0.0",
     "mocha": "^3.2.0",
     "nyc": "^11.0.1",