Try fixing travis matrix

Author: yann-eugone

.travis.yml

@@ -7,21 +7,17 @@ php:
   - 7.3
 
 env:
-  - SYMFONY_VERSION="3.3.*"
   - SYMFONY_VERSION="3.4.*"
-  - SYMFONY_VERSION="4.0.*"
-  - SYMFONY_VERSION="4.1.*"
   - SYMFONY_VERSION="4.2.*"
+  - SYMFONY_VERSION="4.3.*"
 
 matrix:
   exclude:
     # Symfony >= 4.0 PHP requirement is ^7.1.3
-    - php: 7.0
-      env: SYMFONY_VERSION="4.0.*"
-    - php: 7.0
-      env: SYMFONY_VERSION="4.1.*"
     - php: 7.0
       env: SYMFONY_VERSION="4.2.*"
+    - php: 7.0
+      env: SYMFONY_VERSION="4.3.*"
 
 sudo: false