Sobre restrições de branch
Os branches em repositórios que pertencem às organizações podem ser configurados para que apenas determinados usuários ou equipes possam fazer push no branch.
Protected branches are available in public repositories with GitHub Free, and in public and private repositories with GitHub Pro, GitHub Team, GitHub Enterprise Cloud, and GitHub Enterprise Server. The ability to restrict branches is a type of branch protection that's available for public and private repositories owned by organizations in GitHub Team, GitHub Enterprise Cloud, and GitHub Enterprise Server.
When you enable branch restrictions, only users or teams that have been given permission can push to the protected branch. For more information, see "Enabling branch restrictions" and "About protected branches." You can view and edit the users or teams with push access to a protected branch in the protected branch's settings.
Você pode dar acesso push a um branch protegido apenas a usuários ou equipes instalados com acesso write a um repositório.
Pessoas com permissões de administrador a um repositório sempre podem fazer push em um branch protegido.
Note: If "Include administrators" is selected, you've enabled required status checks on the branch, and if any status checks fail, any attempt to push changes to the protected branch will also fail, even for people with admin permissions. For more information, see "Enabling required status checks."