upd 7.4 image on travis (#357)

andreybolonin · Nyholm · commit 965daa34cf3b · 2019-12-26T11:30:52.000+01:00
diff --git a/.travis.yml b/.travis.yml
@@ -28,7 +28,7 @@ matrix:
 
           # Test the latest stable release
         - php: 7.3
-        - php: 7.4snapshot
+        - php: 7.4
 
           # Force some major versions of Symfony
         - php: 7.3
