Drop phpstan check and simplify travis config

.travis.yml

@@ -2,9 +2,7 @@ language: php
 
 php:
   - 5.6
-  - 7.1
-  - 7.2
-  - 7.3
+  - 7.4
 
 env:
   global:
@@ -20,25 +18,19 @@ matrix:
     - php: 7.2
       env: PHPCS=1 DEFAULT=0
 
-    - php: 7.2
-      env: PHPSTAN=1 DEFAULT=0
-
 before_script:
   - if [[ $TRAVIS_PHP_VERSION != 7.2 && $TRAVIS_PHP_VERSION != 7.3 ]]; then phpenv config-rm xdebug.ini; fi
 
   - composer update --no-interaction
 
   - if [[ $PHPCS = 1 ]]; then composer require cakephp/cakephp-codesniffer:^3.0; fi
-  - if [[ $PHPSTAN = 1 ]]; then composer require phpstan/phpstan:^0.9; fi
 
 script:
   - if [[ $DEFAULT = 1 ]]; then vendor/bin/phpunit; fi
   - if [[ $COVERAGE = 1 ]]; then vendor/bin/phpunit --coverage-clover=clover.xml; fi
 
   - if [[ $PHPCS = 1 ]]; then vendor/bin/phpcs -p --extensions=php --standard=vendor/cakephp/cakephp-codesniffer/CakePHP ./src ./tests; fi
 
-  - if [[ $PHPSTAN = 1 ]]; then vendor/bin/phpstan analyse src; fi
-
 after_success:
   - if [[ $COVERAGE = 1 ]]; then bash <(curl -s https://codecov.io/bash); fi