update venv command

tests/test_11_uninstall.py

@@ -0,0 +1,7 @@
+from tests import TESTPY_VERSION
+
+def test_uninstall():
+    from pythonbrew.commands.uninstall import UninstallCommand
+    for py_version in TESTPY_VERSION:
+        c = UninstallCommand()
+        c.run_command(None, [py_version])