Cleanup Travis CI file

- Mention each PHP version explicitly
- Remove redundant comment
- Only run secondary checks once (on latest PHP version)

.travis.yml

@@ -4,14 +4,13 @@ language: php
 php:
   - 7.4snapshot
   - 7.3
+  - 7.2
   - 7.1
   - 7.0
   - 5.6
   - 5.5
   - 5.4
-
-# This triggers builds to run on the new (faster) TravisCI infrastructure.
-# See: http://docs.travis-ci.com/user/workers/container-based-infrastructure/
+  - 5.3
 
 # As the latest Debian not supporting PHP 5.3 to 5.5 anymore, we need to force using 'trusty'.
 dist: trusty
@@ -28,28 +27,27 @@ matrix:
   include:
     - php: 7.4snapshot
       allow_failures: true
-    - php: 7.2
+    - php: 7.3
       env: SNIFF=1
-    - php: 5.5
-    - php: 5.4
     - php: 5.3
       # As the latest Debian not supporting PHP 5.3 anymore, we need to force using 'precise'.
       dist: precise
 
   fast_finish: true
 
 before_install:
-  - npm set loglevel error
-  - npm set progress false
+  - if [[ "$SNIFF" == "1" ]];then npm set loglevel error; fi
+  - if [[ "$SNIFF" == "1" ]];then npm set progress false; fi
 
 install:
   - npm install -g jsonlint
 
 script:
-  - find . -type f -name "*.json" -print0 | xargs -0 -n1 jsonlint -q
-  - find . -type f -name "*.php" -print0 | xargs -0 -n1 php -l
-  - composer validate
+  - if [[ "$SNIFF" == "1" ]];then find . -type f -name "*.json" -print0 | xargs -0 -n1 jsonlint -q; fi
+  - if [[ "$SNIFF" == "1" ]];then find . -type f -name "*.php" -print0 | xargs -0 -n1 php -l; fi
+  - if [[ "$SNIFF" == "1" ]];then composer validate; fi
   - travis_wait composer install --no-interaction --no-progress --no-scripts --no-suggest --optimize-autoloader --prefer-dist --verbose
-  - if [[ "$SNIFF" == "1" ]]; then composer install-codestandards; fi
-  - if [[ "$SNIFF" == "1" ]]; then ./vendor/bin/phpcs; fi
-  - ./vendor/bin/security-checker -n security:check --end-point=http://security.symfony.com/check_lock
+  - composer install-codestandards
+  - ./vendor/bin/phpcs -i
+  - ./vendor/bin/phpcs
+  - if [[ "$SNIFF" == "1" ]];then ./vendor/bin/security-checker -n security:check --end-point=http://security.symfony.com/check_lock; fi