Fix GitHub URLs and comment bodies (dotnet#77)

Author: Eilon

src/TriageBuildFailures/GitHub/GitHubClientWrapper.cs

@@ -95,7 +95,7 @@ public async Task<IEnumerable<IssueComment>> GetIssueComments(GitHubIssue issue)
 
         public async Task CreateComment(GitHubIssue issue, string comment)
         {
-            comment += $"\n\nThis comment was made automatically. If there is a problem contact {Config.BuildBuddyUsername}.";
+            comment = $"This comment was made automatically. If there is a problem contact {Config.BuildBuddyUsername}.\n\n{comment}";
 
             await Client.Issue.Comment.Create(issue.RepositoryOwner, issue.RepositoryName, issue.Number, comment);
         }

src/TriageBuildFailures/Handlers/HandleTestFailures.cs

@@ -138,7 +138,7 @@ This test failed on {build.BranchName}.
 
             foreach (var test in testAggregates)
             {
-                Reporter.Output($"Adding test failure comment to issue {test.Key}");
+                Reporter.Output($"Adding test failure comment to issue {test.Key.HtmlUrl}");
                 await GHClient.CommentOnTest(build, test.Key, test.Value);
             }
         }