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/diffusion/ssh/DiffusionSSHMercurialServeWorkflow.php

@@ -32,11 +32,11 @@ final class DiffusionSSHMercurialServeWorkflow
     $args = $this->getArgs();
 
     if (!$args->getArg('stdio')) {
-      throw new Exception("Expected `hg ... --stdio`!");
+      throw new Exception('Expected `hg ... --stdio`!');
     }
 
     if ($args->getArg('command') !== array('serve')) {
-      throw new Exception("Expected `hg ... serve`!");
+      throw new Exception('Expected `hg ... serve`!');
     }
 
     $command = csprintf('hg -R %s serve --stdio', $repository->getLocalPath());

src/applications/diffusion/ssh/DiffusionSSHSubversionServeWorkflow.php

@@ -35,7 +35,7 @@ final class DiffusionSSHSubversionServeWorkflow
   protected function executeRepositoryOperations() {
     $args = $this->getArgs();
     if (!$args->getArg('tunnel')) {
-      throw new Exception("Expected `svnserve -t`!");
+      throw new Exception('Expected `svnserve -t`!');
     }
 
     $command = csprintf(

src/applications/diffusion/ssh/DiffusionSSHWorkflow.php

@@ -8,7 +8,7 @@ abstract class DiffusionSSHWorkflow extends PhabricatorSSHWorkflow {
 
   public function getRepository() {
     if (!$this->repository) {
-      throw new Exception("Call loadRepository() before getRepository()!");
+      throw new Exception('Call loadRepository() before getRepository()!');
     }
     return $this->repository;
   }
@@ -62,7 +62,7 @@ abstract class DiffusionSSHWorkflow extends PhabricatorSSHWorkflow {
           'Unrecognized repository path "%s". Expected a path like '.
           '"%s".',
           $path,
-          "/diffusion/X/"));
+          '/diffusion/X/'));
     }
 
     $callsign = $matches[1];