parseHelp(last, out) {
    const help = parseHelp(out);
    const alias = [];

    let results = Object.keys(help.flags).map(key => {
      const flag = help.flags[key];

      if (flag.alias) {
        alias.push({...flag, name: flag.alias});
      }

      flag.name = key;

      return flag;
    }).map(this.item(last, '--'), this);

    results = [...results, ...alias.map(this.item(last.replace(':', '_'), '-'), this)];
    results = results.filter(r => r.name !== '--help' && r.name !== '-h');

    return results;
  }
Parse-help wrapper. Invokes parse-help with stdout result, returning the
list of completion items for flags / alias.

@param {String}   last  Last word in COMP_LINE (completed line in command line)
@param {String}   out   Help output