Update babel to 2.9.0

[pyup-bot]

This PR updates Babel from 2.8.0 to 2.9.0.

Changelog

### 2.9.0 ``` ------------- Upcoming version support changes ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ * This version, Babel 2.9, is the last version of Babel to support Python 2.7, Python 3.4, and Python 3.5. Improvements ~~~~~~~~~~~~ * CLDR: Use CLDR 37 – Aarni Koskela (734) * Dates: Handle ZoneInfo objects in get_timezone_location, get_timezone_name - Alessio Bogon (741) * Numbers: Add group_separator feature in number formatting - Abdullah Javed Nesar (726) Bugfixes ~~~~~~~~ * Dates: Correct default Format().timedelta format to 'long' to mute deprecation warnings – Aarni Koskela * Import: Simplify iteration code in "import_cldr.py" – Felix Schwarz * Import: Stop using deprecated ElementTree methods "getchildren()" and "getiterator()" – Felix Schwarz * Messages: Fix unicode printing error on Python 2 without TTY. – Niklas Hambüchen * Messages: Introduce invariant that _invalid_pofile() takes unicode line. – Niklas Hambüchen * Tests: fix tests when using Python 3.9 – Felix Schwarz * Tests: Remove deprecated 'sudo: false' from Travis configuration – Jon Dufresne * Tests: Support Py.test 6.x – Aarni Koskela * Utilities: LazyProxy: Handle AttributeError in specified func – Nikiforov Konstantin (724) * Utilities: Replace usage of parser.suite with ast.parse – Miro Hrončok Documentation ~~~~~~~~~~~~~ * Update parse_number comments – Brad Martin (708) * Add __iter__ to Catalog documentation – CyanNani123 ``` ### 2.8.1 ``` ------------- This is solely a patch release to make running tests on Py.test 6+ possible. Bugfixes ~~~~~~~~ * Support Py.test 6 - Aarni Koskela (747, 750, 752) ```

Links

- PyPI: https://pypi.org/project/babel - Changelog: https://pyup.io/changelogs/babel/ - Homepage: http://babel.pocoo.org/ - Docs: https://pythonhosted.org/Babel/