Before:
  runtime ale_linters/zeek/zeek.vim

After:
  call ale#linter#Reset()

Execute(The zeek handler should parse input correctly):
  AssertEqual
  \ [
  \   {
  \     'lnum': 2,
  \     'text': 'unknown identifier bar, at or near "bar"'
  \   },
  \ ],
  \ ale_linters#zeek#zeek#HandleErrors(bufnr(''), [
  \ 'error in /tmp/foo.zeek, line 2: unknown identifier bar, at or near "bar"'
  \ ])