Merge pull request #47 from deguif/update-travis-configuration

Update travis configuration

.travis.yml

@@ -9,10 +9,10 @@ cache:
 php:
     - 7.2
     - 7.3
+    - 7.4
 
 before_install:
     - composer self-update
-    - if [ "$DEPENDENCIES" = "dev" ]; then perl -pi -e 's/^}$/,"minimum-stability":"dev"}/' composer.json; fi;
 
 install:
     - composer update $COMPOSER_FLAGS