Update release notes for version 0.5.5 (unreleased)
Update release notes for version 0.5.5 (unreleased)

This will be released soon, hopefully after #1 is resolved and we have
XML formatting for Jenkins runs. I'm frontloading the work here to make
releasing said version easier.

Change-Id: I3d46ff87a337ce31584d4427f19f8c6c9a534a01
Reviewed-on: https://gerrit.causes.com/19255
Tested-by: jenkins <d95b56ce41a2e1ac4cecdd398defd7414407cc08@causes.com>
Reviewed-by: Aiden Scandella <1faf1e8390cdac9204f160c35828cc423b7acd7b@causes.com>

davecarter/scss-lint,cih/scss-lint,teoljungberg/scss-lint,golmansax/scss-lint,gajus/scss-lint,dwayhs/scss-lint,baileyparker/scss-lint,ingdir/scss-lint,bkeepers/scss-lint,philipgiuliani/scss-lint,gatero/scss-lint,ivantsepp/scss-lint,chatzipan/scss-lint,leseulsteve/scss-lint