Address gosec findings

Mostly handling unhandled errors appropriately.
If logging to STDERR fails, we panic. Added #nosec
comments to findings we are OK with.

pkg/util/util.go

@@ -12,7 +12,7 @@ func GetCertPool(paths []string) (*x509.CertPool, error) {
 	}
 	pool := x509.NewCertPool()
 	for _, path := range paths {
-		data, err := ioutil.ReadFile(path)
+		data, err := ioutil.ReadFile(path) // #nosec G304
 		if err != nil {
 			return nil, fmt.Errorf("certificate authority file (%s) could not be read - %s", path, err)
 		}