Upload new dev version

Makefile

@@ -24,4 +24,5 @@ i-have-tested-with-testpypi-and-am-ready-to-release:
 	python3 -m twine upload --repository pypi dist/django_admin_confirm-$(VERSION)
 
 install-testpypi:
+	pip uninstall django_admin_confirm
 	python -m pip install --index-url https://test.pypi.org/simple/ django_admin_confirm==${VERSION}