Bump php version && fix phpunit config errors

Author: eddturtle

.gitignore

@@ -2,4 +2,5 @@
 composer.lock
 vendor
 !.gitkeep
-tests/output
+tests/output
+.phpunit.cache

README.md

@@ -2,6 +2,8 @@
 
 PHP wrapper for the qpdf library.
 
+Currently requires PHP 7.4+ and the `qpfd` library installed (`sudo apt install qpdf`).
+
 Basic Examples:
 
 ### Merge

composer.json

@@ -10,11 +10,11 @@
         }
     ],
     "require": {
-        "php" : ">=7.2",
+        "php" : ">=7.4",
         "mikehaertl/php-shellcommand": "^1.5.0"
     },
     "require-dev": {
-        "phpunit/phpunit": "~8.0||~9.0"
+        "phpunit/phpunit": "~8.0||~9.0||~10.0"
     },
     "autoload": {
         "psr-4": {

phpunit.xml

@@ -1,12 +1,15 @@
 <?xml version="1.0" encoding="UTF-8"?>
-<phpunit backupGlobals="false"
-         backupStaticAttributes="false"
+<phpunit xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+         xsi:noNamespaceSchemaLocation="https://schema.phpunit.de/10.5/phpunit.xsd"
+         backupGlobals="false"
          bootstrap="vendor/autoload.php"
          cacheResult="false"
-         colors="true">
-    <testsuites>
-        <testsuite name="DirectUpload Test Suite">
-            <directory suffix=".php">./tests/</directory>
-        </testsuite>
-    </testsuites>
-</phpunit>
+         colors="true"
+         cacheDirectory=".phpunit.cache"
+         backupStaticProperties="false">
+  <testsuites>
+    <testsuite name="QPDF Test Suite">
+      <directory suffix=".php">./tests/</directory>
+    </testsuite>
+  </testsuites>
+</phpunit>