Prepare the 2.12.0 release

CHANGELOG

@@ -1,4 +1,4 @@
-* 2.12.0 (2019-XX-XX)
+* 2.12.0 (2019-10-05)
 
  * added the spaceship operator ("<=>"), useful when using an arrow function in the "sort" filter
  * added support for an "arrow" function on the "sort" filter

src/Environment.php

@@ -38,12 +38,12 @@ use Twig\TokenParser\TokenParserInterface;
  */
 class Environment
 {
-    const VERSION = '2.12.0-DEV';
+    const VERSION = '2.12.0';
     const VERSION_ID = 21200;
     const MAJOR_VERSION = 2;
     const MINOR_VERSION = 12;
     const RELEASE_VERSION = 0;
-    const EXTRA_VERSION = 'DEV';
+    const EXTRA_VERSION = '';
 
     private $charset;
     private $loader;