Make retcode the number of failed checks

certo/__main__.py

@@ -8,7 +8,6 @@ Options:
    -t SECONDS --timeout=SECONDS       Timeout for SSL Handshake [default: 5]
 """
 import logging
-from pprint import pprint
 
 from docopt import docopt
 
@@ -30,7 +29,11 @@ if __name__ == "__main__":
         logging.info(f"Getting CERT from {hs}")
         results.append(check_host_certificate_expiration(hs, days_to_expiration))
 
+    failed = list(r for r in results if not r.check_successful)
+
     if output_as_json:
         print(json_output(results))
     else:
         print(default_output(results))
+
+    exit(len(failed))