This 0.23.1 release fixes a long-running bug that was overwriting
kconfig and download_url metadata, causing lots of confusion when
people tried to cross down info regarding tuxbuilds.
Complete list of changes going in:
* commands: submit_tuxbuild: require download_url in schema
* commands: submit_tuxbuild: avoid extra slash
* submit_tuxbuild: add config file url to the metadata