exec is highlighted as a keyword instead of a builtin

[Beefster09]

This would be correct for Python 2, but given that this is a plugin for 3.latest, this is incorrect behavior.

• Editor name and version: Atom 1.27.0 x64
• Platform: Windows 10
• Color scheme: Any (Atom Dark should work fine)
• MagicPython version: 1.0.12
• 5-10 lines of surrounding code:

    if args.post_ingest is not None:
        code_obj = compile(args.post_ingest, '<snippet>', 'single')
        snippet_logger = logctl.get_logger('<snippet>')
        def post_ingest():
            try:
                exec(code_obj, {'log': snippet_logger}, {})
            except:
                log.exception("Error in --post-ingest snippet")

[1st1]

This will be part of the upcoming release.