Use swarming in capture_archives CT task and capture archives in parallel

ct/isolates/capture_archives.isolate

 # Copyright (c) 2016 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 {
   'includes': [
-    'py.isolate',
   ],
   'conditions': [
     ['OS=="linux"', {
       'variables': {
         'files': [
-          '../../../../../bin/create_pagesets',
+          '../../../../../bin/capture_archives',
         ],
         'command': [
-          '../../../../../bin/create_pagesets',
+          '../../../../../bin/capture_archives',
           '-logtostderr',
           '--start_range=<(START_RANGE)',
           '--num=<(NUM)',
           '--pageset_type=<(PAGESET_TYPE)',
         ],
       },
     }],
   ]
 }