Merge pull request hubotio#533 from github/version-bump-2.6.1

Version bump to 2.6.1

update for v2.5.0 release

* update hubot and hubot-scripts version ranges so it doesn't install 3.0.0

Version bump to 2.5.4

release 2.5.3

Bump package version and 

Bump versions and update CHANGELOG.md

Bump hubot version to 2.5.0

release 2.4.8

bump to version 2.4.7

release 2.4.6