Fix a couple of core tests under Python 3.

IPython/core/tests/test_interactiveshell.py

@@ -219,4 +219,4 class TestSafeExecfileNonAsciiPath(unittest.TestCase):
     def test_1(self):
         """Test safe_execfile with non-ascii path
         """
-        _ip.shell.safe_execfile(self.fname, raise_exceptions=True)
+        _ip.shell.safe_execfile(self.fname, {}, raise_exceptions=True)

IPython/core/tests/test_magic.py

@@ -324,7 +324,10 def check_cpaste(code, should_fail=False):
     _ip.user_ns['code_ran'] = False
 
     src = StringIO()
-    src.encoding = None   # IPython expects stdin to have an encoding attribute
+    try:
+        src.encoding = None  # IPython expects stdin to have an encoding attribute
+    except Exception:
+        pass                 # ...but it's a read-only attribute in Python 3
     src.write('\n')
     src.write(code)
     src.write('\n--\n')