Do not install tox into tox

frenzymadness · int19h · commit f14ba78c5ce4 · 2021-09-28T13:29:29.000-07:00
Having tox as a dependency in requirements files means that
it's also installed in all the tox environments.
diff --git a/tests/requirements.txt b/tests/requirements.txt
@@ -6,7 +6,6 @@ pytest
 pytest-xdist
 pytest-cov
 pytest-timeout
-tox
 
 ## Used by test helpers:
 
diff --git a/tests/requirements27.txt b/tests/requirements27.txt
@@ -8,7 +8,6 @@ pytest-xdist<2
 
 pytest-cov
 pytest-timeout
-tox
 
 ## Used by test helpers:
 
diff --git a/tests/requirements35.txt b/tests/requirements35.txt
@@ -6,7 +6,6 @@ pytest
 pytest-xdist
 pytest-cov
 pytest-timeout
-tox
 
 ## Used by test helpers:
 
