Before:
  call ale#assert#SetUpFixerTest('yaml', 'yamlfmt')

After:
  Restore

  call ale#assert#TearDownFixerTest()

Execute(The yamlfmt callback should return the correct default command):
  AssertEqual
  \ {'command': ale#Escape('yamlfmt') . '  -in'},
  \ ale#fixers#yamlfmt#Fix(bufnr(''))