Handle more ResourceWarning issues. admin.py - remove unneeded close. mailer.py - close debug log file. indexer.py - close read of version file memorydb.py - close python files being compled. Similiar to instance. not sure why it's compoing things and not just letting instance do it. .travis.ymv disable all except 3.9-dev till we get a handle on errors. also increase errors to 50 from 20.

try:
    from html import escape as html_escape_  # python 3

    def html_escape(str, quote=False):
        # html_escape under python 3 sets quote to true by default
        # make it python 2 compatible
        return html_escape_(str, quote=quote)
except ImportError:
    # python 2 fallback
    from cgi import escape as html_escape  # noqa: F401