Chore: Update travis script to run php-cs-fixer and php-stan scripts

Author: bensquire

.gitignore

@@ -1,2 +1,3 @@
 vendor/
 build/
+.idea/

.php_cs.dist

@@ -3,7 +3,7 @@
 
 $finder = PhpCsFixer\Finder::create()
     ->exclude('vendor')
-    ->in([__DIR__ . '/src']);
+    ->in([__DIR__ . '/src', __DIR__ . '/tests']);
 
 return PhpCsFixer\Config::create()
     ->setUsingCache(false)      //Remove for performance improvements

.travis.yml

@@ -4,9 +4,14 @@ dist: trusty
 php:
   - "7.1"
   - "7.2"
+  - "7.3"
 
 before_install:
   - composer self-update
   - composer install --dev --no-interaction --prefer-source
 
-script: vendor/bin/phpunit
+jobs:
+  include:
+    - script: ./vendor/bin/php-cs-fixer fix . --dry-run --stop-on-violation
+    - script: ./vendor/bin/phpstan analyse ./src --level=max
+    - script: ./vendor/bin/phpunit

phpunit.xml

@@ -2,7 +2,7 @@
 <phpunit colors="true" verbose="true" bootstrap="./tests/Bootstrap.php">
     <testsuites>
         <testsuite name="PHPImageOptim Tests">
-            <directory suffix="Test.php" phpVersion="5.6.0" phpVersionOperator=">=">tests/PHPImageOptim</directory>
+            <directory suffix="Test.php" phpVersion="7.1.0" phpVersionOperator=">=">tests/PHPImageOptim</directory>
         </testsuite>
     </testsuites>