Update PHPUnit

Author: vearutop

.travis.yml

@@ -1,17 +1,14 @@
 language: php
 php:
-  - nightly
+  - 8.0
   - 7.4
   - 7.3
   - 7.2
   - 7.1
   - 7.0
   - 5.6
-  - 5.5
-  - 5.4
 
 sudo: false
-dist: trusty
 
 ## Cache composer bits
 cache:

composer.json

@@ -10,8 +10,8 @@
     "swaggest/json-diff": "^3.5.1"
   },
   "require-dev": {
-    "phpunit/phpunit": "4.8.35",
-    "phpunit/php-code-coverage": "2.2.4"
+    "phpunit/phpunit": "^5",
+    "phpunit/php-code-coverage": "^4"
   },
   "license": "MIT",
   "authors": [
@@ -36,7 +36,7 @@
   },
   "config": {
     "platform": {
-      "php": "5.4.45"
+      "php": "5.6.0"
     }
   }
 }