Buildifier 0.12.0 includes initial support for reformatting .bzl files.
- Reformat all the bzl files.
- Expand the travis check to check the .bzl files also.
* Fix up the skylint warning about depset usage.
* Remove the reassignment of max_bazel_version.
This was flagged by skylint, the reality is _is_at_most() does the parsing
so it shouldn't be parsed before sent on the way.
* Fix up the skylint warning about depset usage.
* Fixup the skylint warning about re-exports.
Just move to the explicit re-export form.
* Fix the fail() call to use the right variable.
skylint flagged this variable as undefined, but it it seems like this
was never right and should have been "key" all along.
* Fixup docstring formatting for skylint.