fix set_repo_permissions

fix command_plugins/github/config.py syntax

Use new teams API for AddUserToTeam and SetRepoPermissions

Use new org-scope team API endpoint to add repo to team

Merge pull request #106 from timgates42/bugfix_typo_safeguard

Merge pull request #109 from Netflix/remove_collab

Merge pull request #110 from Netflix/exclude_nf_employees_from_addcollab

add check against whether user is a member of a set of teams in the org.

add hook to remove collaborators in nathanexplosion

Merge pull request #108 from Netflix/update_slack_sdk

update to python 3.8

update dependencies for rtmbot and duo_client to allow for newer versions. this will let us build on newer versions of python and use patched versions of the rtmbot

docs: fix simple typo, safegurad -> safeguard

Merge pull request #105 from noamran/update-travis-plugin

Updating the Travis Plugin to use travis-ci.com by default