Remove `ci-management-1` node

Removes the `ci-management-1` node. It's not used, and it ran out of disk space. By removing it, we don't need to bother about fixing the disk space issue and we can save some cash.

Removes by:
- removing from the Vagrantfile
- removing node definition from Hiera
- removing Graphite module from `modules/` and Puppetfile