3.1.4

• [CVE-2021-27938] Prevent echoing request variable (Steve Boyd) - 45b6278
• Update QueuedJobDescriptor.php (Vinnie) - 319c835
• Update Travis builds to include PHP 7, update PHPUnit to 5.7 (Robbie Averill) - b2ea2be
• Check Subsite class exists before checking SubsiteID (Steve Boyd) - 993104f
• Fix(mutex) make the mutex update check for finished or running jobs (Stephen McMahon) - ba18a08
• Fix(QueuedJobService): Valid $messages data being overwritten (jcarter) - e501fb9