Bring back perf

Author: jaraco

tox.ini

@@ -28,6 +28,13 @@ commands =
 	diff-cover coverage.xml --html-report diffcov.html
 	diff-cover coverage.xml --fail-under=100
 
+[testenv:perf]
+use_develop = False
+deps =
+    ipython
+commands =
+    python -m timeit -s 'import importlib_metadata' -- 'importlib_metadata.distribution("ipython")'
+
 [testenv:release]
 skip_install = True
 deps =