Before:
  call ale#assert#SetUpLinterTest('ruby', 'ruby')

After:
  call ale#assert#TearDownLinterTest()

Execute(The default command should be correct):
  AssertLinter 'ruby', ale#Escape('ruby') . ' -w -c %t'

Execute(The executable should be configurable):
  let g:ale_ruby_ruby_executable = 'foobar'

  AssertLinter 'foobar', ale#Escape('foobar') . ' -w -c %t'