Remove obsolete WMS tests

Those tests are broken since refactoring ol ol.parser.XML made by
fredj/ol3@305dd1ce230c03a293078e6501f817e346c2f2c6 and brought to this branch
by htulipe/ol3@5e094bb1733cbef9bab88e41ce79b4fef11d020b

Since they are obsolete (PR #1610), it is OK to remove them here.