Publish books with the most-open policy

Summary: Ref T4558. When publishing a new Diviner book, use the most-open policy instead of `PhabricatorPolicies::POLICY_USER`.

Test Plan: Ran `diviner generate` in a directory which didn't have published Diviner documentation.

Reviewers: #blessed_reviewers, epriestley

Reviewed By: #blessed_reviewers, epriestley

Subscribers: epriestley, Korvin

Maniphest Tasks: T4558

Differential Revision: https://secure.phabricator.com/D13254

src/applications/diviner/publisher/DivinerLivePublisher.php

@@ -12,7 +12,7 @@ final class DivinerLivePublisher extends DivinerPublisher {
       if (!$book) {
         $book = id(new DivinerLiveBook())
           ->setName($book_name)
-          ->setViewPolicy(PhabricatorPolicies::POLICY_USER)
+          ->setViewPolicy(PhabricatorPolicies::getMostOpenPolicy())
           ->save();
       }