Change double quotes to single quotes.

Summary: Ran `arc lint --apply-patches --everything` over rP, mainly to change double quotes to single quotes where appropriate. These changes also validate that the `ArcanistXHPASTLinter::LINT_DOUBLE_QUOTE` rule is working as expected.

Test Plan: Eyeballed it.

Reviewers: #blessed_reviewers, epriestley

Reviewed By: #blessed_reviewers, epriestley

Subscribers: epriestley, Korvin, hach-que

Differential Revision: https://secure.phabricator.com/D9431

src/applications/macro/controller/PhabricatorMacroMemeController.php

@@ -31,8 +31,8 @@ final class PhabricatorMacroMemeController
 
     $upper_text = strtoupper($upper_text);
     $lower_text = strtoupper($lower_text);
-    $mixed_text = md5($upper_text).":".md5($lower_text);
-    $hash = "meme".hash("sha256", $mixed_text);
+    $mixed_text = md5($upper_text).':'.md5($lower_text);
+    $hash = 'meme'.hash('sha256', $mixed_text);
     $xform = id(new PhabricatorTransformedFile())
       ->loadOneWhere('originalphid=%s and transform=%s',
         $file->getPHID(), $hash);