Unable to add teams to a repo

## Problem Description
Safe Settings is able to remove teams from a repo based on configuration, but not able to add teams to a repo.

### What is actually happening
^^

### What is the expected behavior
The GitHub teams should be added to the repo.

### Error output, if available
No errors. There is a comment in the code refering to the GitHub API. Has the endpoint changed for github.com and this is not reflected in code?

## Context
We are trying to run safe-settings with suborg's settings files.

### Are you using the hosted instance of probot/settings or running your own?
We are running probot in our own container.

### If running your own instance, are you using it with github.com or GitHub Enterprise?
Github.com

#### Version of probot/settings
Latest.

#### Version of GitHub Enterprise
NA