Ensure that ipython gets installed via testing extra.

Author: jaraco

exercises.ini

@@ -1,6 +1,7 @@
 [discovery]
 warmup = import importlib_metadata
 exercise = importlib_metadata.distribution("ipython")
+extras = testing
 
 [entry_points()]
 warmup = import importlib_metadata
@@ -9,7 +10,9 @@ exercise = importlib_metadata.entry_points()
 [cached distribution]
 warmup = import importlib_metadata; importlib_metadata.distribution("ipython")
 exercise = importlib_metadata.distribution("ipython")
+extras = testing
 
 [uncached distribution]
 warmup = import importlib, importlib_metadata
 exercise = importlib.invalidate_caches(); importlib_metadata.distribution("ipython")
+extras = testing

setup.cfg

@@ -51,7 +51,10 @@ testing =
 	pep517
 	pyfakefs
 	flufl.flake8
-	pytest-perf
+	pytest-perf>=0.4
+
+	# for performance tests
+	ipython
 
 docs =
 	# upstream