Merge pull request #51 from Codeception/travis-php-7.3

Run tests on PHP 7.3

Author: Naktibalda

.travis.yml

@@ -6,6 +6,7 @@ env:
 php:
   - 7.1
   - 7.2
+  - 7.3
 
 before_script:
   - wget https://robo.li/robo.phar
@@ -14,4 +15,4 @@ before_script:
 
 script:
   - php robo.phar test cli
-  - php robo.phar test "unit -g core"
+  - php robo.phar test "unit -g core"