Update github_old.go (#916)

pkg/detectors/github_old/github_old.go

@@ -20,7 +20,7 @@ var _ detectors.Detector = (*Scanner)(nil)
 var (
 	// Oauth token
 	// https://developer.github.com/v3/#oauth2-token-sent-in-a-header
-	keyPat = regexp.MustCompile(`(?i)(?:github)[^\.].{0,40}[ =:'"]+([a-f0-9]{40})\b`)
+	keyPat = regexp.MustCompile(`(?i)(?:github|gh|pat)[^\.].{0,40}[ =:'"]+([a-f0-9]{40})\b`)
 
 	// TODO: Oauth2 client_id and client_secret
 	// https://developer.github.com/v3/#oauth2-keysecret
@@ -38,7 +38,7 @@ type userRes struct {
 // Keywords are used for efficiently pre-filtering chunks.
 // Use identifiers in the secret preferably, or the provider name.
 func (s Scanner) Keywords() []string {
-	return []string{"github"}
+	return []string{"github","gh","pat"}
 }
 
 // FromData will find and optionally verify GitHub secrets in a given set of bytes.