[TASK] Allow PHP up to 7.2.x

Also remove the dependency on the phpunit extension.

.travis.yml

@@ -11,6 +11,7 @@ matrix:
   include:
   - php: 7.0
   - php: 7.1
+  - php: 7.2
 
 install:
   - composer install

composer.json

@@ -26,7 +26,7 @@
         "source": "https://github.com/oliverklee/tea"
     },
     "require": {
-        "php": "~7.0.0 || ~7.1.0",
+        "php": "~7.0.0 || ~7.1.0 || ~7.2.0",
         "typo3/cms-core": "^7.6 || ^8.7"
     },
     "require-dev": {

ext_emconf.php

@@ -10,8 +10,8 @@ $EM_CONF[$_EXTKEY] = [
     'version' => '2.0.x-dev',
     'constraints' => [
         'depends' => [
+            'php' => '7.0.0-7.2.99',
             'typo3' => '7.6.0-8.7.99',
-            'phpunit' => '4.0.0-5.9.99',
         ],
     ],
 ];