Remove test for visual with name

The Visual class does not have an attribute name anymore. Consequently,
we can not expect the test to work.

test/test_urdf.py

@@ -244,20 +244,6 @@ def test_link_multiple_visual(self):
         robot.add_link(link)
         self.xml_and_compare(robot, xml)
 
-    def test_visual_with_name(self):
-        xml = '''<?xml version="1.0"?>
-<robot name="test" version="1.0">
-  <link name="link">
-    <visual name="alice">
-      <geometry>
-        <cylinder length="1" radius="1"/>
-      </geometry>
-      <material name="mat"/>
-    </visual>
-  </link>
-</robot>'''
-        self.parse_and_compare(xml)
-
     def test_link_multiple_collision(self):
         xml = '''<?xml version="1.0"?>
 <robot name="test" version="1.0">