list collaborators
-X GET is optional
$ curl -u 'USERNAME' -X GET https://api.github.com/repos/USERNAME/REPONAME/collaborators
add a collaborator
$ curl -u 'USERNAME' -X PUT -d '' https://api.github.com/repos/USERNAME/REPONAME/collaborators/COLLABORATORNAME
delete a collaborator
-d '' is optional
$ curl -u 'USERNAME' -X DELETE -d '' https://api.github.com/repos/USERNAME/REPONAME/collaborators/COLLABORATORNAME