Remove strict typing for PHP 5.6 compatibility

Refs #50.

Author: ADmad

composer.json

@@ -10,12 +10,12 @@
         }
     ],
     "require": {
-        "php": ">=7.2.0",
+        "php": ">=5.6.0",
         "composer-plugin-api": "^1.0 || ^2.0"
     },
     "require-dev": {
-        "cakephp/cakephp-codesniffer": "^4.1",
-        "composer/composer": "^2.0@RC",
+        "cakephp/cakephp-codesniffer": "^3.3",
+        "composer/composer": "^2.0",
         "phpunit/phpunit": "^8.5 || ^9.3"
     },
     "autoload": {

src/Plugin.php

@@ -1,6 +1,4 @@
 <?php
-declare(strict_types=1);
-
 namespace Cake\Composer;
 
 use Composer\Composer;
@@ -88,8 +86,8 @@ public function postAutoloadDump(Event $event)
     public function findPlugins(
         array $packages,
         array $pluginDirs = ['plugins'],
-        string $vendorDir = 'vendor'
-    ): array {
+        $vendorDir = 'vendor'
+    ) {
         $plugins = [];
 
         foreach ($packages as $package) {
@@ -133,7 +131,7 @@ public function findPlugins(
      * @param string $vendorDir The path to the vendor dir.
      * @return string
      */
-    public function getFullPath(string $path, string $vendorDir): string
+    public function getFullPath($path, $vendorDir)
     {
         if (preg_match('{^(?:/|[a-z]:|[a-z0-9.]+://)}i', $path)) {
             return rtrim($path, '/');
@@ -154,7 +152,7 @@ public function getFullPath(string $path, string $vendorDir): string
      * @param string|null $root The root directory. Defaults to a value generated from `$configFile`.
      * @return void
      */
-    public function writeConfigFile(string $configFile, array $plugins, ?string $root = null): void
+    public function writeConfigFile($configFile, array $plugins, $root = null)
     {
         $root = $root ?: dirname(dirname($configFile));
 
@@ -214,7 +212,7 @@ public function writeConfigFile(string $configFile, array $plugins, ?string $roo
      * @param string $vendorDir Path to composer-vendor dir.
      * @return string Absolute file path.
      */
-    public function getConfigFilePath(string $vendorDir): string
+    public function getConfigFilePath($vendorDir)
     {
         return $vendorDir . DIRECTORY_SEPARATOR . 'cakephp-plugins.php';
     }
@@ -226,7 +224,7 @@ public function getConfigFilePath(string $vendorDir): string
      * @return string The package's primary namespace.
      * @throws \RuntimeException When the package's primary namespace cannot be determined.
      */
-    public function getPrimaryNamespace(PackageInterface $package): string
+    public function getPrimaryNamespace(PackageInterface $package)
     {
         $primaryNs = null;
         $autoLoad = $package->getAutoload();