Remove unused import (flutter#309)

Author: goderbauer

packages/fuchsia_ctl/lib/src/emulator.dart

@@ -2,8 +2,6 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-import 'dart:io';
-
 import 'package:file/file.dart';
 import 'package:file/local.dart';
 import 'package:meta/meta.dart';