Fixing issue with multibyte characters in node

closes #38

lib/adapters/http.js

@@ -52,15 +52,15 @@ module.exports = function httpAdapter(resolve, reject, config) {
   // Create the request
   var transport = parsed.protocol === 'https:' ? https : http;
   var req = transport.request(options, function (res) {
-    var responseText = '';
+    var responseBuffer = [];
     res.on('data', function (chunk) {
-      responseText += chunk;
+      responseBuffer.push(chunk);
     });
 
     res.on('end', function () {
       var response = {
         data: transformData(
-          responseText,
+          Buffer.concat(responseBuffer).toString('utf8'),
           res.headers,
           config.transformResponse
         ),
@@ -83,4 +83,4 @@ module.exports = function httpAdapter(resolve, reject, config) {
 
   // Send the request
   req.end(data);
-};
+};