Bump factory-boy from 3.0.1 to 3.1.0

Bumps [factory-boy](https://github.com/FactoryBoy/factory_boy) from 3.0.1 to 3.1.0.
- [Release notes](https://github.com/FactoryBoy/factory_boy/releases)
- [Changelog](https://github.com/FactoryBoy/factory_boy/blob/master/docs/changelog.rst)
- [Commits](FactoryBoy/factory_boy@3.0.1...3.1.0)

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

test_reqs.txt

@@ -6,5 +6,5 @@ django-jenkins==0.110.0
 pep8==1.7.1
 pyflakes==2.2.0
 django-markwhat==1.6.2
-factory_boy==3.0.1
+factory_boy==3.1.0
 six==1.15.0