prow/github/fakegithub/fakegithub.go
func (f *FakeClient) IsMember(org, user string) (bool, error) {
	for _, m := range f.OrgMembers[org] {
		if m == user {
			return true, nil
		}
	}
	return false, nil
}
func (f *FakeClient) IsMember(org, user string) (bool, error) {
	for _, m := range f.OrgMembers[org] {
		if m == user {
			return true, nil
		}
	}
	return false, nil
}
// IsMember returns true if user is in org.