Allow build steps to create URI artifacts

Summary: Ref T1049.  This allows build steps to create URI artifacts, which can be used to link to external builds and other resources.

Test Plan: Used a build step in an external library to test the creation of a URI artifact and verified it appeared correctly.

Reviewers: epriestley, #blessed_reviewers

Reviewed By: epriestley, #blessed_reviewers

Subscribers: epriestley, Korvin

Maniphest Tasks: T1049

Differential Revision: https://secure.phabricator.com/D10173

src/applications/harbormaster/storage/build/HarbormasterBuildArtifact.php

@@ -13,7 +13,7 @@ final class HarbormasterBuildArtifact extends HarbormasterDAO
 
   const TYPE_FILE = 'file';
   const TYPE_HOST = 'host';
-  const TYPE_BUILD_STATE = 'buildstate';
+  const TYPE_URI = 'uri';
 
   public static function initializeNewBuildArtifact(
     HarbormasterBuildTarget $build_target) {
@@ -69,6 +69,11 @@ final class HarbormasterBuildArtifact extends HarbormasterDAO
           ->setObjectName(pht('Drydock Lease'))
           ->setHeader($lease->getID())
           ->setHref('/drydock/lease/'.$lease->getID());
+      case self::TYPE_URI:
+        return id(new PHUIObjectItemView())
+          ->setObjectName($data['name'])
+          ->setHeader($data['uri'])
+          ->setHref($data['uri']);
       default:
         return null;
     }