added exit for missing programs

bitwardenBackup.py

@@ -368,10 +368,13 @@ if __name__ == "__main__":
     # check if required programs are installed
     if not shutil.which(bitwarden_cli_executable):
         print("Bitwarden CLI ({}) cannot be found. Please make sure it is installed and executable.".format(bitwarden_cli_executable))
+        sys.exit(1)
     elif not shutil.which(gpg_executable):
         print("GPG ({}) cannot be found. Please make sure it is installed and executable.".format(gpg_executable))
+        sys.exit(1)
     elif not shutil.which(secure_delete_executable):
         print("SRM/sdelete.exe ({}) cannot be found. Please make sure it is installed and executable.".format(secure_delete_executable))
+        sys.exit(1)
 
     client = client.ProxyKmipClient(config_file=pykmip_client_config_file)
     client.open()