Updated more references to now unsupported PHP versions

.travis.yml

@@ -33,7 +33,7 @@ before_script:
 
 script:
   - composer ci
-  - if [[ ! -z "$DOCKERFILE_CHANGED" && "${TRAVIS_PHP_VERSION}" == "7.2" ]]; then docker build -t shlink-docker-image:temp . ; fi
+  - if [[ ! -z "$DOCKERFILE_CHANGED" && "${TRAVIS_PHP_VERSION}" == "7.4" ]]; then docker build -t shlink-docker-image:temp . ; fi
 
 after_success:
   - rm -f build/clover.xml
@@ -55,4 +55,4 @@ deploy:
     skip_cleanup: true
     on:
       tags: true
-      php: '7.2'
+      php: '7.4'