Bump dnspython from 1.16.0 to 2.1.0

Bumps [dnspython](https://github.com/rthalley/dnspython) from 1.16.0 to 2.1.0.
- [Release notes](https://github.com/rthalley/dnspython/releases)
- [Changelog](https://github.com/rthalley/dnspython/blob/master/doc/whatsnew.rst)
- [Commits](rthalley/dnspython@v1.16.0...v2.1.0)

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

requirements.txt

@@ -16,7 +16,7 @@ Deprecated==1.2.7
 Django==2.2.18
 django-auth-ldap==2.2.0
 djangorestframework==3.12.1
-dnspython==1.16.0
+dnspython==2.1.0
 docutils==0.15.2
 easygui==0.98.1
 flower==0.9.3
@@ -52,7 +52,7 @@ pysafebrowsing==0.1.1
 PySocks==1.7.1
 python-magic==0.4.15
 pytz==2019.2
-requests==2.22.0
+requests==2.25.1
 s3transfer==0.2.1
 smmap2==2.0.5
 sqlparse==0.2.4