closes #83

Thanks! Let me know once this is ready for review.

@tswast - Almost ready,
I'm debating about having SQLA 1.4 a dev requirement (for tests)
and about 1 issue of backward compatibility, which might be an issue only if someone actually passed inline to BigQueryCompiler

I'm debating about having SQLA 1.4 a dev requirement (for tests)

Ideally we'd have some test sessions for our minimum requirements as well as the latest supported. I've created #85 to track this.

In the meantime, I'm okay adding a dev requirement.

@alonme Apologies, but I just "blackened" all the source in this repo. It will most likely cause some conflicts.

In good news, we do now have "constraints" files in the testing/ directory which allow us to test against specific package versions for each of our test sessions. Plain ol' pytest should still work, but to use that multi-version testing, we can run with nox http://nox.thea.codes/

See: #177