**Is your feature request related to a problem? Please describe.**
It's frustrating there's no option to turn off decompress. There are situations where you want to do this. Ex: having a service that collects data, but doesn't analyze it. which then passes to another service immediately/eventually.

While data is waiting or in traffic to next stop, it should stay compressed. The difference in byte size is huge (for me, 60MB vs 1-2MB). 

**Describe the solution you'd like**
Add an option to the request to not automatically decompress for me. I'm a big boy, I can handle it myself later.

**Describe alternatives you've considered**
There are none except user another lib or write own http req (which is ridiculous just to turn off a auto feature).


I can submit a PR if no one else wants to do it (it's not hard to add). But let me know how you'd like the option to be passed in? An extra options key? `axios({ url: ..., method: ..., decompress: false })` , or adding option to an existing option?


test/unit/adapters/http.js
res.end('4567');
    }).listen(4444, function () {
      proxy = http.createServer(function (request, response) {
        var parsed = url.parse(request.url);
        var opts = {
          host: parsed.hostname,
          port: parsed.port,
          path: parsed.path
        };
        http.get(opts, function (res) {
          var body = '';
          res.on('data', function (data) {
            body += data;
          });
          res.on('end', function () {
            response.setHeader('Content-Type', 'text/html; charset=UTF-8');
            response.end(body + '1234');
          });
        });
      }).listen(4000, function () {
        // s
        process.env.http_proxy = 'http://localhost:4000/';
        axios.get('http://localhost:4444/').then(function (res) {
          assert.equal(res.data, '45671234', 'should use proxy set by process.env.http_proxy');
          done();
        });
      });
    });
  });
  it('should not use proxy for domains in no_proxy', function (done) {