add head from simple-get

asset.js

@@ -9,7 +9,7 @@ const pump = require('pump')
 const uuid = require('uuid/v4')
 const url = require('url')
 const fs = require('fs')
-
+const { head } = require('simple-get')
 /**
  * The `Asset` class represents a container for an external asset
  * that has semantic associations with other objects.