Regex used in rm-key command is too lax
Regex used in rm-key command is too lax

Basically the issue is that 'gitlab-shell rm-key key-2' removes all keys that match "key-2" pattern.
"key-20", "key-25", etc.
This change makes the regex used in the sed command more strict.

gitlabhq/gitlab-shell,cui-liqiang/gitlab-shell,yonh/gitlab-shell,bozaro/gitlab-shell,bozaro/gitlab-shell,fscherwi/gitlab-shell,dpursehouse/gitlab-shell,Jadaw1n/gitlab-shell,copystudy/gitlab-shell,achako/gitlab-shell,feedhenry/gitlab-shell,dwrensha/gitlab-shell,yonh/gitlab-shell,sonalkr132/gitlab-shell,cui-liqiang/gitlab-shell,gitlabhq/gitlab-shell,feedhenry/gitlab-shell,achako/gitlab-shell,dpursehouse/gitlab-shell,sonalkr132/gitlab-shell,Jadaw1n/gitlab-shell,kotaro-dev/gitlab-shell-1-9-4,gitlabhq/gitlab-shell,fscherwi/gitlab-shell,copystudy/gitlab-shell,dwrensha/gitlab-shell,kotaro-dev/gitlab-shell-1-9-4