Remove Join Policy from Phame

Summary: Drops Join Policy, uses Edit Policy where needed. Allows anyone with Blog Edit permissions to post and edit any post on that blog. Fixes T5371

Test Plan: Draft Post as chad, see post, log in with notchad, edit that post and publish it.

Reviewers: epriestley

Reviewed By: epriestley

Subscribers: Korvin

Maniphest Tasks: T5371

Differential Revision: https://secure.phabricator.com/D14444

src/applications/phame/controller/post/PhamePostEditController.php

@@ -36,7 +36,7 @@ final class PhamePostEditController extends PhamePostController {
         ->requireCapabilities(
           array(
             PhabricatorPolicyCapability::CAN_VIEW,
-            PhabricatorPolicyCapability::CAN_JOIN,
+            PhabricatorPolicyCapability::CAN_EDIT,
           ))
         ->executeOne();
       if (!$blog) {