a8n: Setup rcache for tests
Created by: mrnugget
We accidently relied on this being setup by another test when these
tests were still in the graphqlbackend
package. Now that they've
moved, the rcache
used by the GitHubSource
was not setup for
testing.
The result was that the tests took ~16 seconds to run on CI until the rcache connection times out (without an error, since it's a cache) and 90+ seconds on my machine.