Makefile does pip upgrade for making .venv
diff --git a/Makefile b/Makefile
index c2ab1e8..a084265 100644
--- a/Makefile
+++ b/Makefile
@@ -57,5 +57,6 @@
 
 $(VENV):
 	$(PYTHON) -m venv $@
+	pip install --upgrade pip
 	pip install pytest
 	pip install -e .