End-to-end command -> add ability to support custom commits of drivers about performance

[dennwc]

we need to carry all the build environments for all languages in one container

This is not true. All you need to build a driver is to have Go 1.12+ locally and have access to Docker. It will re-create the environment there automatically.

bblfsh-performance should not perform build during the performance test

We want to test different branches and we won't ever have images published for those. We need to build it locally, there is no way around it. And it's not as hard as you may think.

[lwsanty]

item 2. concerns me and I think it should be skipped
there're different drivers on different languages and for this case we need to carry all the build environments for all languages in one container with bblfsh-performance...

imo bblfsh-performance should not perform build during the performance test.
usage cases that I see:

• CI execution: here we always gonna deal with driver images that are present in docker hub so no extra builds required
• debugging by developer usually developer is able to create an image himself locally, then this image name can be passed to bblfsh-performance for an installation to bblfshd.

wdyt @dennwc @bzz @kuba-- @creachadair ?

[bzz]

there're different drivers on different languages and for this case we need to carry all the build environments for all languages in one container with bblfsh-performance...

Build of language specific parts is hidden inside docker, so there is no need to do that, as @dennwc explain.

It may be ok to skip building in the beginning and make it would only with existing tags, but going further we would definitely want to be able to run it on random revision and that thus we need to plan/keep in mind the ability to build image by calling the docker.