Before:
  call ale#assert#SetUpLinterTest('markdown', 'rumdl')

After:
  call ale#assert#TearDownLinterTest()

Execute(The default command should be correct):
  AssertLinter 'rumdl', ale#Escape('rumdl') . ' server --stdio'

Execute(The executable should be configurable):
  let b:ale_markdown_rumdl_executable = 'rumdl_custom'

  AssertLinter 'rumdl_custom', ale#Escape('rumdl_custom') . ' server --stdio'

Execute(The server options should be configurable):
  let b:ale_markdown_rumdl_options = '--some-flag'

  AssertLinter 'rumdl', ale#Escape('rumdl') . ' server --stdio --some-flag'