Announcement: Sceptre 2.5.0 release

[zaro0508]

Hello Sceptre fans. I wanted to announce Sceptre v2.5.0 availability. Please read the changelog for more info on what has been updated. Along with the Sceptre app updates there have also been many recent changes around the infrastructure (docker images, builds scripts, circleci workflows, 3rd party services, etc..) to get Sceptre back into shape for releases. I would like to thank the following fans for helping to make this happen: @rdkr , @tarkatronic , @zxiiro , and @craighurley. They have been very helpful getting us to a state where we can create releases more often. If you are interested in joining us for lively Sceptre (or just general AWS discussion) we are all on the #sceptre slack channel.