Composer 1.1.0 was release on May 10, 2016:
Created attachment 170373 [details]
Thanks for bringing it up. But you didn't provide a patch to the port... so here is one.
I wanted to leave that for the port maintainer, since the port maintainer probably knows best how to perform the upgrade.
A commit references this bug:
Date: Sun May 29 08:55:42 UTC 2016
New revision: 416089
Update to version 1.1.0
Submitted by: Yonas Yanfa
Approved by: maintainer