[Accessibility]: appdash Go module dependancy

[mcwalrus]

Problem description

Paths to sourcegraph.com/sourcegraph/appdash and sourcegraph.com/sourcegraph/appdash-data are no longer available.

This is causing build error with external tool https://github.com/99designs/gqlgen - see issue #2862.

Expected behavior

On command:

go get github.com/99designs/gqlgen-contrib

to run without error. Instead:

go: github.com/99designs/gqlgen-contrib@upgrade (v0.1.0) indirectly requires sourcegraph.com/sourcegraph/appdash-data@v0.0.0-20151005221446-73f23eafcf67: unrecognized import path "sourcegraph.com/sourcegraph/appdash-data": reading https://sourcegraph.com/sourcegraph/appdash-data?go-get=1: 404 Not Found

This is returning missing URL 404 on paths.

Additional details

This is blocking our build process for development and production.

It would be great if this could be priority to resolve.

Thanks

### Tasks

[Karl-Sparticle]

any way to resolve it?

[mallsk23]

Are there plans to fix this issue, experiencing the same when trying to pull in the following which is an indirect dependency:

sourcegraph.com/sourcegraph/appdash-data@v0.0.0-20151005221446-73f23eafcf67