package.json: use the https repo URL.

package.json

@@ -7,7 +7,7 @@
   "license": "Apache License, Version 2.0, http://www.apache.org/licenses/LICENSE-2.0",
   "repository": {
     "type": "git",
-    "url": "git://github.com/thomaspark/bootswatch.git"
+    "url": "https://github.com/thomaspark/bootswatch.git"
   },
   "engines": {
     "node": ">= 0.8.11"