Use http package for requests

lib/helpers/api_helper.dart

@@ -5,14 +5,13 @@ import 'package:comunic/helpers/account_credentials_helper.dart';
 import 'package:comunic/models/api_request.dart';
 import 'package:comunic/models/api_response.dart';
 import 'package:comunic/models/config.dart';
+import 'package:http/http.dart' as http;
 
 /// API Helper
 ///
 /// @author Pierre HUBERT
 
 class APIHelper {
-  final _httpClient = HttpClient();
-
   /// Execute a [request] on the server and returns a [APIResponse]
   ///
   /// This method should never throw but the response code of the [APIResponse]
@@ -31,16 +30,6 @@ class APIHelper {
         request.addString("userToken2", tokens.tokenTwo);
       }
 
-      // Prepare request body
-      String requestBody = "";
-      request.args.forEach((key, value) => requestBody +=
-          Uri.encodeQueryComponent(key) +
-              "=" +
-              Uri.encodeQueryComponent(value) +
-              "&");
-
-      List<int> bodyBytes = utf8.encode(requestBody);
-
       // Determine server URL
       final path = config().apiServerUri + request.uri;
       Uri url;
@@ -49,22 +38,16 @@ class APIHelper {
       else
         url = Uri.https(config().apiServerName, path);
 
-      //Connect to server
-      final connection = await _httpClient.postUrl(url);
-      connection.headers.set("Content-Length", bodyBytes.length.toString());
-      connection.headers
-          .set("Content-Type", "application/x-www-form-urlencoded");
-      connection.add(bodyBytes);
-
-      final response = await connection.close();
+      final response = await http.post(
+        url.toString(),
+        body: request.args,
+        encoding: utf8
+      );
 
       if (response.statusCode != HttpStatus.ok)
         return APIResponse(response.statusCode, null);
 
-      //Save & return response
-      final responseBody = await response.transform(utf8.decoder).join();
-
-      return APIResponse(response.statusCode, responseBody);
+      return APIResponse(response.statusCode, utf8.decode(response.bodyBytes));
     } on Exception catch (e) {
       print(e.toString());
       print("Could not execute a request!");