upgrade pip

scripts/addons/cam/__init__.py

@@ -37,6 +37,7 @@ try:
 except ImportError:
     # pip install required python stuff
     subprocess.check_call([sys.executable, "-m", "ensurepip"])
+    subprocess.check_call([sys.executable, "-m", "pip", "install", "--upgrade", " pip"])
     subprocess.check_call([sys.executable, "-m", "pip", "install", "shapely","Equation","opencamlib"])