Fix new services declaration

Author: terox

src/Vivait/StringGeneratorBundle/Resources/config/services.yml

@@ -30,6 +30,8 @@ services:
 
     vivait_generator.generator.uuid_string:
         class: Vivait\StringGeneratorBundle\Generator\UuidGenerator
+        tags:
+            - { name: vivait_generator.generator, alias: 'uuid_string' }
 
     vivait_generator.randomlib:
         class: RandomLib\Factory