## About The Pull Request
simply adds a new unit test, `language_key_conflicts`, ported from my
work on monkestation.
it is exactly what it says on the tin - it ensures two languages do not
have the same exact key. i don't think that's an issue here, but better
safe than sorry.
## Why It's Good For The Game
more unit test coverage for subtle bugs that might be hard to realize is
always nice
## Changelog
No user-facing changes.
