Bump html5lib from 0.9999999 to 0.999999999 in /requirements

Bumps [html5lib](https://github.com/html5lib/html5lib-python) from 0.9999999 to 0.999999999.
- [Release notes](https://github.com/html5lib/html5lib-python/releases)
- [Changelog](https://github.com/html5lib/html5lib-python/blob/master/CHANGES.rst)
- [Commits](https://github.com/html5lib/html5lib-python/compare/0.9999999...0.999999999)

---
updated-dependencies:
- dependency-name: html5lib
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <support@github.com>

requirements/requirements.txt

@@ -10,7 +10,7 @@ Django==1.7.10
 easy-thumbnails==2.2
 eav-django==1.4.7
 gunicorn==19.3.0
-html5lib==0.9999999
+html5lib==0.999999999
 Pillow==2.9.0
 pisa==3.0.33
 psycopg2==2.6.1