Merge pull request #45 from keradus/phpunit_master

Extend Travis config to add tests against dev-master of PHPUnit

Author: johnkary

.travis.yml

@@ -9,13 +9,15 @@ php:
 
 env:
   - PHPUNIT=7.*
+  - PHPUNIT=dev-master MIN_STABILITY=dev
 
 cache:
   directories:
     - $HOME/.composer
 
 before_script:
   - phpenv config-rm xdebug.ini || true
+  - if [ "$MIN_STABILITY" != "" ]; then composer config minimum-stability $MIN_STABILITY; fi
   - composer require phpunit/phpunit:${PHPUNIT}
 
 script: