Undid previous changes to DummyServer. A previous commit added a
"makeWorld" or "getWorld" method to DummyServer, because we thought we
needed a world for entity generation.
Revert "Undid previous changes to DummyServer. A previous commit added a "makeWorld" or "getWorld" method to DummyServer, because we thought we needed a world for entity generation. "

This reverts commit ee77efc4c50380f1f4dd74912708544589bdfdf9.
Undid changes to DummyServer. Any visible changes in DummyServer should
be discarded. This commit removes the getWorld method added to the dummy
server, which was thought to be needed for entity generation. Neither
world nor server were needed for that test, so we have removed changes.