Update .travis.yml

Author: divineniiquaye

.travis.yml

@@ -17,10 +17,11 @@ before_install:
 
 install:
     - composer update --no-interaction
-    - composer require squizlabs/php_codesniffer --dev
 
 script:
-    - ./vendor/bin/phpcs --standard=psr12 --colors src tests
+    - ./vendor/bin/phpcs
+    - ./vendor/bin/phpstan
+    - ./vendor/bin/psalm
     - ./vendor/bin/phpunit --coverage-clover=coverage.xml
 
 after_success: