Use sushi git module hosted on github instead bitbucket

[laenzlinger]

First of all, thank you very much for open sourcing this cool generic UI. This makes debugging so much more efficient (before I was using grpcurl which was working but much more complicated)

I have a small suggestion to change the remote URL for the grpc API to the public github repo

This would make it easier for open source project to use this UI.

[stez-mind]

Thanks, indeed this was a mistake on our end :(

For these, we prefer to use relative paths, so we'll do it slightly different than your PR