drop the spread, use object.assign

Author: jonchurch

Diff for: lib/response.js

@@ -708,7 +708,7 @@ res.get = function(field){
 
 res.clearCookie = function clearCookie(name, options) {
   // Force cookie expiration by setting expires to the past
-  const opts = { path: '/', ...options, expires: new Date(1) }
+  const opts = Object.assign({ path: '/' } , options, { expires: new Date(1) })
   // ensure maxAge is not passed
   delete opts.maxAge