set encoding: null in test HTTP requests

from the 'request' docs:

encoding: Encoding to be used on setEncoding of response data. If null, the body is returned as a Buffer. Anything else (including the default value of undefined) will be passed as the encoding parameter to toString() (meaning this is effectively utf8 by default).

test/test.js

@@ -606,7 +606,7 @@ describe("Crafatar", function() {
       var location = locations[description];
       (function(location) {
         it("should return correct HTTP response for " + description, function(done) {
-          request.get(location.url, {followRedirect: false}, function(error, res, body) {
+          request.get(location.url, {followRedirect: false, encoding: null}, function(error, res, body) {
             assert.ifError(error);
             assert_headers(res);
             assert(res.headers["x-storage-type"]);