Tests(tox): Limit `VIRTUALENV_PIP` version for Python 3.4

diff --git a/tox.ini b/tox.ini
index 7d7449e17a6d2a670ecb63a2cff6e2c47ed06f59..81400c7d417b2d81e9a2f038f1bf3fe2b9d449f8 100644 (file)
--- a/tox.ini
+++ b/tox.ini
@@ -20,3 +20,5 @@ commands =
     {envpython} -c "import struct; print(struct.calcsize('P') * 8)"
     ./test_all
 passenv = HOME
+setenv =
+    VIRTUALENV_PIP = 19.1.1