add some light tests

IPython/core/tests/test_display.py

@@ -194,6 +194,12 b' def test_displayobject_repr():'
     j._show_mem_addr = False
     nt.assert_equal(repr(j), '<IPython.core.display.Javascript object>')
 
+def test_progress():
+    p = display.ProgressBar(10)
+    nt.assert_equal(repr(p), '<IPython.core.display.ProgressBar object>')
+    p._show_mem_addr = True
+    nt.assert_equal(p._repr_html_(), "<progress style='width:100%' max='10' value='0'></progress>")
+
 def test_json():
     d = {'a': 5}
     lis = [d]