[DRE-maint] Bug#1063802: Update to latest release (1.2.x)

[Jérôme Charaoui]

Package: src:ruby-concurrent
Version: 1.1.6+dfsg-5

Hello,

I'm currently working on upgrading the Puppet packages in Debian and one 
of the requirements is a newer version of ruby-concurrent, at least 1.2.2.

The reason is that memory leaks were identified in earlier versions.

Unless there's a reason to proceed in a more coordinated manner (if so, 
let me know), I'll upload an updated package myself some time soon.

Thanks,

-- Jérôme