google-calendar: Stop printing events unless the verbose option is set.

Currently, the integration prints all reminders to the terminal.
Set logging level to info when --verbose is set, and switched `print` to
`logging.info`, to restrict that output to only when the --verbose
option is set.

Author: Niloth-p

zulip/integrations/google/google-calendar

@@ -74,6 +74,8 @@ except ImportError:
 
 if not options.zulip_email:
     parser.error("You must specify --user")
+if options.verbose:
+    logging.getLogger().setLevel(logging.INFO)
 
 
 def get_credentials() -> Credentials:
@@ -159,7 +161,7 @@ def send_reminders() -> Optional[None]:
                     line = f"{summary} is today."
                 else:
                     line = "{} starts at {}".format(summary, start.strftime("%H:%M"))
-                print("Sending reminder:", line)
+                logging.info("Sending reminder: %s", line)
                 messages.append(line)
                 keys.add(key)