panic: nil dereference in GithubProvider.getResponse()

[briandealwis]

runtime error: invalid memory address or nil pointer dereference [signal SIGSEGV: segmentation violation code=0x1 addr=0x0 pc=0xb25f07]
at github.com/google/triage-party/pkg/provider.(*GithubProvider).getResponse (github.go:64)
at github.com/google/triage-party/pkg/provider.(*GithubProvider).IssuesListByRepo (github.go:81)
at github.com/google/triage-party/pkg/hubbub.(*Engine).updateIssues (issue.go:87)
at github.com/google/triage-party/pkg/hubbub.(*Engine).cachedIssues (issue.go:46)
at github.com/google/triage-party/pkg/hubbub.(*Engine).SearchIssues.func1 (search.go:66)

The problem seems to be here:

triage-party/pkg/provider/github.go

Lines 77 to 82 in f6fe365

	func (p *GithubProvider) IssuesListByRepo(ctx context.Context, sp SearchParams) (i []*Issue, r *Response, err error) {
	opt := p.getIssueListByRepoOptions(sp)
	gi, gr, err := p.client.Issues.ListByRepo(ctx, sp.Repo.Organization, sp.Repo.Project, opt)
	i = p.getIssues(gi)
	r = p.getResponse(gr)
	return

It looks like the go-github returns nil pointers for requests that error.