Switch to raw string to match typing at prompt

IPython/core/tests/test_magic.py

@@ -453,7 +453,7 b' def test_timeit_arguments():'
 @dec.skipif(execution.profile is None)
 def test_prun_quotes():
     "Test that prun does not clobber string escapes (GH #1302)"
-    _ip.magic("prun -q x = '\t'")
+    _ip.magic(r"prun -q x = '\t'")
     nt.assert_equal(_ip.user_ns['x'], '\t')
 
 def test_extension():