Test groups and thoughts on query tests

[grobie]

@ncabatoff and I had a discussion and I drafted some thoughts.

It would be great to have some test groups in order to test different loads of exporters and test to run on them. We came up with the idea of having different types of tests like query performance #8, ingestion speed #7, federation, etc. I sketched a raw config which would allow for the configuration of such tests.

For the output we should come up with a standard generic format so that we can write a compare tool similar to benchcmp #4.

Here is the gist we talked about https://gist.github.com/grobie/a68911b05a95aef9ff3000c2ac8d65a6