fixing InteractiveShell instantiation in test

IPython/extensions/tests/test_rmagic.py

@@ -2,12 +2,10 b' import numpy as np'
 from IPython.core.interactiveshell import InteractiveShell
 from IPython.extensions import rmagic
 
-ip = None
-def setup():
-    global ip
-    ip = InteractiveShell()
+ip = get_ipython()
     ip.magic('load_ext rmagic')
 
+
 def test_push():
     rm = rmagic.RMagics(ip)
     ip.push({'X':np.arange(5), 'Y':np.array([3,5,4,6,7])})