Change the mode of the directory created by PhutilKeyValueCacheDirectory
Summary: Change the mode of the directory created by PhutilKeyValueCacheDirectory from 0777 to 0755. In general, this directory shouldn't need g+x or o+x permissions.
Test Plan: Ran diviner generate and checked the permissions on the .divinercache directory.
Reviewers: #blessed_reviewers, epriestley
Reviewed By: #blessed_reviewers, epriestley
Subscribers: epriestley, Korvin
Differential Revision: https://secure.phabricator.com/D9947