PHPUnit 6

https://github.com/sebastianbergmann/phpunit/wiki/Release-Announcement-for-PHPUnit-6.0.0

Author: SergeyZ

.travis.yml

@@ -10,24 +10,24 @@ php:
   - hhvm
 
 env:
-  - PHPUNIT=4.7.*     # EOL August 7, 2016
-  - PHPUNIT=4.8.*     # EOL August 7, 2016
-  - PHPUNIT=5.0.*     # EOL February 3, 2017
-  - PHPUNIT=5.1.*     # EOL February 3, 2017
-  - PHPUNIT=5.2.*     # EOL February 2, 2018
-  - PHPUNIT=5.3.*     # EOL February 2, 2018
-  - PHPUNIT=5.4.*     # EOL February 2, 2018
-  - PHPUNIT=5.5.*     # EOL February 2, 2018
-  - PHPUNIT=5.6.*     # EOL February 2, 2018
-  - PHPUNIT=5.7.*     # EOL February 2, 2018
-  - PHPUNIT=^6.0      # EOL February 2, 2018
+  - PHPUNIT=4.7.*
+  - PHPUNIT=4.8.*
+  - PHPUNIT=5.0.*
+  - PHPUNIT=5.1.*
+  - PHPUNIT=5.2.*
+  - PHPUNIT=5.3.*
+  - PHPUNIT=5.4.*
+  - PHPUNIT=5.5.*
+  - PHPUNIT=5.6.*
+  - PHPUNIT=5.7.*
+  - PHPUNIT=6.0.*
 
 matrix:
   exclude:
     - php: 5.6
-      env: PHPUNIT=^6.0
+      env: PHPUNIT=6.0.*
     - php: hhvm
-      env: PHPUNIT=^6.0
+      env: PHPUNIT=6.0.*
 
 cache:
   directories:
@@ -36,7 +36,6 @@ cache:
 before_script:
   - phpenv config-rm xdebug.ini || true
   - composer self-update
-  - composer config minimum-stability dev
   - composer require phpunit/phpunit:${PHPUNIT}
 
 script: