Add PHP versions to Travis-CI test matrix

.travis.yml

@@ -1,21 +1,19 @@
 language: php
 
 php:
-  - 7.0
-  - 7.1
+  - "7.0"
+  - "7.1"
+  - "7.2"
+  - "7.3"
 
 sudo: false
 
 install: travis_retry composer install
 
 script:
   - vendor/bin/phpunit --coverage-clover build/coverage.clover
-  - vendor/bin/phpstan analyse src -c phpstan.neon --level=6 --no-progress -vvv
+  - vendor/bin/phpstan analyse src -c phpstan.neon --level=max --no-progress -vvv
 
 after_script:
   - wget https://scrutinizer-ci.com/ocular.phar
   - php ocular.phar code-coverage:upload --format=php-clover build/coverage.clover
-
-notifications:
-  email:
-    - secure: "iiseqb4k4ckQkMJnZ6Tq3YP5ilTZE4CkVgarsBpPOn+c820nP9QokGpz82D4CTGy/UB1+DfCiFH9YAFrhLP5/9Go1CHP+wYkuz9W+E8q/rm9/nBO0xutoQhOfV3MxMid69E8i4QjODq3w5mOUrmpj/8gl2FyBU1Ro1xgPSYNEQ4="

composer.json

@@ -35,7 +35,7 @@
     },
     "config": {
         "platform": {
-            "php": "7.0"
+            "php": "7.0.33"
         },
         "sort-packages": true
     }