* Fix lint issues
- Move the doc string into the `doc` attributes on the rule/attr calls.
- Move the print() below the load() statements.
* Also run buildifier in --lint=fix mode to catch issues on Travis.
Most notably, this renames/moves a few important identifiers:
//:skylark_library.bzl -> //:bzl_library.bzl
skylark_library -> bzl_library
SkylarkLibraryInfo -> StarlarkLibraryInfo