Check for operating repos doesn't normalize to lowercase

[chrisbsmith]

I just installed this for a repo with an organization whose name contains mixed case. I did not think to mix the case when I provided the GITHUB_REPO_NAME environment variable. This cased a 403 error with an error of {"message":"Not configured for this repository"}. I updated the organization's name in the environment variable to match the case as found in the payload and then the webhook succeeded.

Recommend normalizing both repoSplit[0] and checkSplit[0] to lowercase for comparison.

pull-sizer/main.go

Line 176 in bb557b1

if repoSplit[0] != checkSplit[0] {