Manually spec setuptools for that inplace building.

Author: ionelmc

tox.ini

@@ -44,6 +44,7 @@ deps =
     Django
     objproxies==0.9.4
     hunter
+    setuptools
     cover: pytest-cov
 commands =
     cover: python setup.py clean --all build_ext --force --inplace
@@ -57,6 +58,7 @@ deps =
     readme-renderer
     pygments
     isort
+    setuptools
     setuptools-scm
 skip_install = true
 commands =