dispatcher: fix test result parsing, build ranges for failure alerts, other fixes

go/src/infra/monitoring/messages/testresults.go

 // Copyright 2015 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.
 
 // These structs are for parsing test-results.appspot.com responses.
 
 package messages
 
 // TestResults represents the uploaded results of a set of tests for a build.
 type TestResults struct {
-        BuildNumber       string                `json:"build_number"`
-        SecondsSinceEpoch int64                 `json:"seconds_since_epoch"`
-        Tests             map[string]TestResult `json:"tests"`
+        BuildNumber       string `json:"build_number"`
+        SecondsSinceEpoch int64  `json:"seconds_since_epoch"`
+        // Tests is an arbitrarily nested tree of test names
+        Tests map[string]interface{} `json:"tests"`
 }
 
 // TestResult represents the output of an individual test.
 type TestResult struct {
         Expected string
         Actual   string
         Time     int64
 }