Before:
  call ale#assert#SetUpLinterTest('go', 'gosimple')
  call ale#test#SetFilename('../go_files/testfile2.go')

After:
  call ale#assert#TearDownLinterTest()

Execute(The default gosimple command should be correct):
  AssertLinter 'gosimple',
  \ 'cd ' . ale#Escape(expand('%:p:h')) . ' &&  gosimple .'