Update Travis CI configuration - add builds with PHPUnit 8.5

Author: michalbundyra

.travis.yml

@@ -8,6 +8,7 @@ cache:
 
 env:
   - PHPUNIT_VERSION=dev-master
+  - PHPUNIT_VERSION=~8.5.0
   - PHPUNIT_VERSION=~8.4.0
   - PHPUNIT_VERSION=~8.3.0
   - PHPUNIT_VERSION=~8.2.0
@@ -38,6 +39,8 @@ matrix:
   exclude:
     - php: 7.1
       env: PHPUNIT_VERSION=dev-master
+    - php: 7.1
+      env: PHPUNIT_VERSION=~8.5.0
     - php: 7.1
       env: PHPUNIT_VERSION=~8.4.0
     - php: 7.1
@@ -50,6 +53,8 @@ matrix:
       env: PHPUNIT_VERSION=~8.0.0
     - php: 7
       env: PHPUNIT_VERSION=dev-master
+    - php: 7
+      env: PHPUNIT_VERSION=~8.5.0
     - php: 7
       env: PHPUNIT_VERSION=~8.4.0
     - php: 7