Update travis

Author: MichalGallovic

.travis.yml

@@ -8,19 +8,14 @@ cache:
 matrix:
     fast_finish: true
     include:
-        - php: 7.2
-          env: SETUP=lowest
         - php: 7.3
-          env: SETUP=lowest
-        - php: 7.4
-          env: SETUP=lowest
+          env: SETUP=stable
 
 before_install:
     - travis_retry composer self-update
 
 install:
     - if [[ $SETUP = 'stable' ]]; then travis_retry composer update --prefer-dist --no-interaction --prefer-stable --no-suggest; fi
-    - if [[ $SETUP = 'lowest' ]]; then travis_retry composer update --prefer-dist --no-interaction --prefer-lowest --prefer-stable --no-suggest; fi
 
 script:
     - vendor/bin/phpunit