v2.6.0 release

Signed-off-by: Matthew Peveler <matt.peveler@gmail.com>

add 2.5.0 release to changelog

Signed-off-by: Matthew Peveler <matt.peveler@gmail.com>

Cut version 2.4.0

Update sprockets, cut version 2.3.1

Cut version 2.3

Add changelog for 2.2

Add 2.1.0 changelog notes

Add a few more release notes

Add version 1.5.0 changelog notes

Cut version 1.4.0