Hi axios maintainers,

I'm the maintainer of follow-redirects. According to npm numbers (https://www.npmjs.com/package/axios, https://www.npmjs.com/package/follow-redirects), more than half of follow-redirects usage goes via axios. That is also apparent from several [bug reports](https://github.com/follow-redirects/follow-redirects/issues?q=axios) I received (and which I'm very happy about).

So if there are issues such as https://github.com/axios/axios/pull/1993 or https://github.com/axios/axios/pull/2689, it's probably best to ping us about it at https://github.com/follow-redirects/follow-redirects/issues/new. I'm very happy to fix. Pinning to an old version of follow-redirects will just expose you to bugs.

Please let me know how I can help.

CC: @grumblerchester @emilyemorehouse @realityking @chinesedfan
lib/adapters/http.js
var urlUsername = urlAuth[0] || '';
      var urlPassword = urlAuth[1] || '';
      auth = urlUsername + ':' + urlPassword;
    }
    if (auth) {
      delete headers.Authorization;
    }
    var isHttpsRequest = isHttps.test(protocol);
    var agent = isHttpsRequest ? config.httpsAgent : config.httpAgent;
    var options = {
      path: buildURL(parsed.path, config.params, config.paramsSerializer).replace(/^\?/, ''),
      method: config.method.toUpperCase(),
      headers: headers,
      agent: agent,
      agents: { http: config.httpAgent, https: config.httpsAgent },
      auth: auth
    };
    if (config.socketPath) {
      options.socketPath = config.socketPath;
    } else {
      options.hostname = parsed.hostname;
      options.port = parsed.port;
    }
    var proxy = config.proxy;
    if (!proxy && proxy !== false) {
      var proxyEnv = protocol.slice(0, -1) + '_proxy';
      var proxyUrl = process.env[proxyEnv] || process.env[proxyEnv.toUpperCase()];
      if (proxyUrl) {
        var parsedProxyUrl = url.parse(proxyUrl);
        var noProxyEnv = process.env.no_proxy || process.env.NO_PROXY;