Adds PHP 8.1 to Travis CI matrix

Author: michalbundyra

.travis.yml

@@ -32,6 +32,7 @@ env:
   - PHPUNIT_VERSION=~6.0.0
 
 php:
+  - 8.1
   - 8.0
   - 7.4
   - 7.3
@@ -42,6 +43,51 @@ php:
 matrix:
   fast_finish: true
   exclude:
+    - php: 8.1
+      env: PHPUNIT_VERSION=~9.4.0
+    - php: 8.1
+      env: PHPUNIT_VERSION=~9.3.0
+    - php: 8.1
+      env: PHPUNIT_VERSION=~9.2.0
+    - php: 8.1
+      env: PHPUNIT_VERSION=~9.1.0
+    - php: 8.1
+      env: PHPUNIT_VERSION=~9.0.0
+    - php: 8.1
+      env: PHPUNIT_VERSION=~8.4.0
+    - php: 8.1
+      env: PHPUNIT_VERSION=~8.3.0
+    - php: 8.1
+      env: PHPUNIT_VERSION=~8.2.0
+    - php: 8.1
+      env: PHPUNIT_VERSION=~8.1.0
+    - php: 8.1
+      env: PHPUNIT_VERSION=~8.0.0
+    - php: 8.1
+      env: PHPUNIT_VERSION=~7.5.0
+    - php: 8.1
+      env: PHPUNIT_VERSION=~7.4.0
+    - php: 8.1
+      env: PHPUNIT_VERSION=~7.3.0
+    - php: 8.1
+      env: PHPUNIT_VERSION=~7.2.0
+    - php: 8.1
+      env: PHPUNIT_VERSION=~7.1.0
+    - php: 8.1
+      env: PHPUNIT_VERSION=~7.0.0
+    - php: 8.1
+      env: PHPUNIT_VERSION=~6.5.0
+    - php: 8.1
+      env: PHPUNIT_VERSION=~6.4.0
+    - php: 8.1
+      env: PHPUNIT_VERSION=~6.3.0
+    - php: 8.1
+      env: PHPUNIT_VERSION=~6.2.0
+    - php: 8.1
+      env: PHPUNIT_VERSION=~6.1.0
+    - php: 8.1
+      env: PHPUNIT_VERSION=~6.0.0
+  
     - php: 8.0
       env: PHPUNIT_VERSION=~9.2.0
     - php: 8.0