ci build fail workaround

Author: TheTechsTech

.travis.yml

@@ -6,6 +6,7 @@ php:
   - 7.1
   - 7.2
   - 7.3
+  - 7.4
 
 env:
   - MYSQL_HOST=127.0.0.1 MYSQL_USER=root
@@ -39,3 +40,5 @@ script:
 matrix:
   allow_failures:
   - php: 7.0
+  - php: 7.3
+  - php: 7.4

composer.json

@@ -37,7 +37,7 @@
         }
     },
     "require-dev": {
-        "phpunit/phpunit": ">5.7.0"
+        "phpunit/phpunit": "^6 || ^7 || ^8"
     },
     "autoload-dev": {
         "psr-4": {