csgo_coachcommand: Add `.uncoach` command

[marqdevx]

Hello! I've added the .uncoach command so instead of typing coach in the console or doing a retry, user can just type that to get back on spec mode.

Also updated .travis.yml as it is on https://github.com/splewis/csgo-pug-setup/blob/master/.travis.yml

Feel free to edit the branch 😄