add pypitest test in tox.ini

Author: skasberger

tox.ini

@@ -92,3 +92,11 @@ recreate = True
 commands =
     pip freeze
     python -c "import pyDataverse; print(pyDataverse.__name__); print(pyDataverse.__version__)"
+
+[testenv:pypitest]
+description = install from test pypi
+skip_install = True
+recreate = True
+commands =
+    pip install --index-url https://test.pypi.org/simple/ pyDataverse
+    pip freeze