Bump django from 2.2 to 2.2.13 in /lesson01/wangshukang/devops2020

Bumps [django](https://github.com/django/django) from 2.2 to 2.2.13.
- [Release notes](https://github.com/django/django/releases)
- [Commits](django/django@2.2...2.2.13)

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

Author: dependabot[bot]

lesson01/wangshukang/devops2020/requirements.txt

@@ -1,4 +1,4 @@
-Django==2.2
+Django==2.2.13
 mysqlclient==2.0.1
 PyMySQL==0.9.3
 pytz==2020.1