chore(package): update less to version 3.0.4

Closes #15

Author: greenkeeper[bot]

package.json

@@ -30,7 +30,7 @@
     "copy": "^0.3.0",
     "csscomb": "^4.0.0",
     "gulp-google-webfonts": "^0.0.14",
-    "less": "^2.7.2",
+    "less": "^3.0.4",
     "lesshint": "^4.0.0",
     "npm-run-all": "^4.0.0",
     "rimraf": "^2.5.4"