Update to bblfsh 2.9, use -drivers image

[carlosms]

Use bblfsh -drivers image in docker-compose, update travis bblfsh to 2.9.

[smacker]

why don't we use the same drivers image in travis?

[carlosms]

To avoid making it slower. If I'm not mistaken travis won't cache the docker image.
For -drivers it's 480MB vs the normal release at 76MB. The go-driver image is another 14MB, but this one should be cached.

[smacker]

Travis downloads cache too :-D Though 480mb is a lot. Thanks for the clarification!

[carlosms]

🤔 can you point me where to read about travis caching docker images? All I could find requires some workaround (like the ones shared in travis-ci/travis-ci#5358)

[smacker]

I mean when you use travis cache it gets uploaded to a cloud and on each build travis downloads it. So there is no much difference if you download from dockerhub or use travis cache. It's going to be downloaded from amazon s3/google cloud storage anyway.

[carlosms]

I see what you mean now 👍