Pylint in CI

I've been running Pylint and I have found its static analysis to be very helpful. It's also uncovered a number of issues worth looking into in existing code (including loopy and pytential). I think it would be helpful to have a CI job for static analysis.

An issue that should be solved is that pylint does not like pytools.Record because the fields are constructed dynamically, so it issues errors that attributes are missing. I think this ought to be possible to address this with a custom extension.