Bump Linter to latest (0.1.30).

DEPS

 # Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 # for details. All rights reserved. Use of this source code is governed by a
 # BSD-style license that can be found in the LICENSE file.
 
 vars = {
   # The dart_root is the root of our sdk checkout. This is normally
   # simply sdk, but if using special gclient specs it can be different.
   "dart_root": "sdk",
 
   # We use mirrors of all github repos to guarantee reproducibility and
@@ skipping 56 matching lines @@
   "http_multi_server_tag" : "@2.0.3",
   "http_parser_tag" : "@3.1.1",
   "http_tag" : "@0.11.3+9",
   "http_throttle_rev" : "@284344cd357e435c6c8ff9a4a21f02b9e384a541",
   "idl_parser_rev": "@7fbe68cab90c38147dee4f48c30ad0d496c17915",
   "initialize_tag": "@v0.6.2+5",
   "intl_tag": "@0.14.0",
   "isolate_tag": "@1.0.0",
   "jinja2_rev": "@2222b31554f03e62600cd7e383376a7c187967a1",
   "json_rpc_2_tag": "@2.0.4",
-  "linter_rev": "@89f93362c5b48ef5192d77e9a28cf9590542669b", # prerelease 1.30
+  "linter_tag": "@0.1.30",
   "logging_tag": "@0.11.3+1",
   "markdown_tag": "@0.11.2",
   "matcher_tag": "@0.12.0+2",
   "metatest_tag": "@0.2.2+3",
   "mime_rev": "@75890811d4af5af080351ba8a2853ad4c8df98dd",
   "mustache4dart_tag" : "@v1.0.10",
   "oauth2_tag": "@1.0.2",
   "observable_tag": "@0.17.0",
   "observatory_pub_packages_rev": "@26aad88f1c1915d39bbcbff3cad589e2402fdcf1",
   "observe_tag": "@0.15.0",
@@ skipping 145 matching lines @@
       Var("http_throttle_rev"),
   Var("dart_root") + "/third_party/pkg/initialize":
       (Var("github_mirror") % "initialize") + Var("initialize_tag"),
   Var("dart_root") + "/third_party/pkg/intl":
       (Var("github_mirror") % "intl") + Var("intl_tag"),
   Var("dart_root") + "/third_party/pkg/isolate":
       (Var("github_mirror") % "isolate") + Var("isolate_tag"),
   Var("dart_root") + "/third_party/pkg/json_rpc_2":
       (Var("github_mirror") % "json_rpc_2") + Var("json_rpc_2_tag"),
   Var("dart_root") + "/third_party/pkg/linter":
-      (Var("github_mirror") % "linter") + Var("linter_rev"),
+      (Var("github_mirror") % "linter") + Var("linter_tag"),
   Var("dart_root") + "/third_party/pkg/logging":
       (Var("github_mirror") % "logging") + Var("logging_tag"),
   Var("dart_root") + "/third_party/pkg/markdown":
       (Var("github_mirror") % "markdown") + Var("markdown_tag"),
   Var("dart_root") + "/third_party/pkg/matcher":
       (Var("github_mirror") % "matcher") + Var("matcher_tag"),
   Var("dart_root") + "/third_party/pkg/metatest":
       (Var("github_mirror") % "metatest") + Var("metatest_tag"),
   Var("dart_root") + "/third_party/pkg/mime":
       (Var("github_mirror") % "mime") + Var("mime_rev"),
@@ skipping 344 matching lines @@
     # Update the Windows toolchain if necessary.
     'name': 'win_toolchain',
     'pattern': '.',
     'action': ['python', 'sdk/build/vs_toolchain.py', 'update'],
   },
   {
     "pattern": ".",
     "action": ["python", Var("dart_root") + "/tools/generate_buildfiles.py"],
   },
 ]