Finally run Travis on PHP 7.4; also bump some dependencies

Author: OndraM

.travis-php74.ini

@@ -0,0 +1 @@
+extension=libzip.so

.travis.yml

@@ -8,7 +8,7 @@ php:
   - '7.1'
   - '7.2'
   - '7.3'
-  - '7.4snapshot'
+  - '7.4'
 
 env:
   global:
@@ -20,10 +20,11 @@ matrix:
   include:
     # Codestyle check build
     - name: 'Code style and static analysis'
-      php: '7.3'
+      php: '7.4'
       env: CHECK_CODESTYLE=1
       before_install:
         - phpenv config-rm xdebug.ini
+        - phpenv config-add .travis-php74.ini
       before_script: ~
       script:
         - composer require phpstan/phpstan # Not part of require-dev, because it won't install on PHP 5.6
@@ -131,6 +132,9 @@ cache:
   directories:
     - $HOME/.composer/cache
 
+before_install:
+  - if [ "$TRAVIS_PHP_VERSION" == "7.4" ]; then phpenv config-add .travis-php74.ini; fi
+
 install:
   - travis_retry composer self-update
   - travis_retry composer update --no-interaction $DEPENDENCIES

composer.json

@@ -21,13 +21,13 @@
   },
   "require-dev": {
     "friendsofphp/php-cs-fixer": "^2.0",
-    "jakub-onderka/php-parallel-lint": "^0.9.2",
+    "jakub-onderka/php-parallel-lint": "^1.0",
     "php-coveralls/php-coveralls": "^2.0",
     "php-mock/php-mock-phpunit": "^1.1",
     "phpunit/phpunit": "^5.7",
     "sebastian/environment": "^1.3.4 || ^2.0 || ^3.0",
     "sminnee/phpunit-mock-objects": "^3.4",
-    "squizlabs/php_codesniffer": "^2.6",
+    "squizlabs/php_codesniffer": "^3.5",
     "symfony/var-dumper": "^3.3 || ^4.0 || ^5.0"
   },
   "suggest": {