Bump python-slugify from 3.0.1 to 3.0.2

Bumps [python-slugify](https://github.com/un33k/python-slugify) from 3.0.1 to 3.0.2.
- [Release notes](https://github.com/un33k/python-slugify/releases)
- [Changelog](https://github.com/un33k/python-slugify/blob/master/CHANGELOG.md)
- [Commits](un33k/python-slugify@3.0.1...3.0.2)

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

requirements.txt

@@ -11,7 +11,7 @@ beautifulsoup4==4.7.1
 httplib2<=0.10.3
 urllib3==1.24.2
 Paver==1.3.4
-python-slugify==3.0.1
+python-slugify==3.0.2
 decorator==4.3.2
 celery==4.2.1
 kombu==4.4.0