Update setup.py

Updated to 3.3.4

Updated the version version number

Merge pull request django-tenants#602 from hanckmann/master

Fix for Using collectstatic_schemas in django 3.1.x fails

Merge pull request django-tenants#510 from BITSOLVER/add_tenant_sync_…

…router

Added setting 'TENANT_SYNC_ROUTER' django-tenants#508

Fixed django-tenants#466 changed setup to allow for Django 3.1

Tidy up of tests

Update CHANGES.rst

See if this fixes read the docs

Updated the version number ready to release