Hotfix/api parsing for half duration lectures (#981)

uni/lib/controller/parsers/parser_schedule.dart

@@ -32,10 +32,15 @@ Future<List<Lecture>> parseSchedule(http.Response response) async {
     final secBegin = lecture['hora_inicio'] as int;
     final subject = lecture['ucurr_sigla'] as String;
     final typeClass = lecture['tipo'] as String;
-    // TODO(luisd): this was marked as a double on the develop branch but the
-    //  tests' example api returns an integer. At the moment there are no
-    //  classes so I can't test this.
-    final blocks = (lecture['aula_duracao'] as int) * 2;
+
+    // Note: aula_duracao is an integer when the lecture is 1 hour long
+    // or 2 hours long and so on. When the lecture is 1.5 hours long, it
+    // returns a double, with the value 1.5.
+    final lectureDuration = lecture['aula_duracao'];
+    final blocks = lectureDuration is double
+        ? (lectureDuration * 2).toInt()
+        : (lectureDuration as int) * 2;
+
     final room =
         (lecture['sala_sigla'] as String).replaceAll(RegExp(r'\+'), '\n');
     final teacher = lecture['doc_sigla'] as String;