Update CHANGELOG.md for 10.1.6
Update CHANGELOG.md for 10.1.6

[ci skip]
iiet/iiet-git,mmkassem/gitlabhq,stoplightio/gitlabhq,dreampet/gitlab,dreampet/gitlab,axilleas/gitlabhq,jirutka/gitlabhq,jirutka/gitlabhq,iiet/iiet-git,axilleas/gitlabhq,jirutka/gitlabhq,mmkassem/gitlabhq,iiet/iiet-git,mmkassem/gitlabhq,dreampet/gitlab,dreampet/gitlab,stoplightio/gitlabhq,axilleas/gitlabhq,stoplightio/gitlabhq,axilleas/gitlabhq,iiet/iiet-git,mmkassem/gitlabhq,stoplightio/gitlabhq,jirutka/gitlabhq