Add the Config class

Add a Config class for storing configuration values such as the
Glassboxx username, password and vendor ID.

.gitignore

@@ -2,3 +2,5 @@
 !*/
 !/.gitignore
 !/composer.json
+!/src/**
+!/tests/**

composer.json

@@ -9,5 +9,18 @@
         }
     ],
     "minimum-stability": "stable",
-    "require": {}
+    "require": {},
+    "autoload": {
+        "psr-4": {
+            "Opdavies\\Glassboxx\\": "src/Glassboxx/"
+        }
+    },
+    "autoload-dev": {
+        "psr-4": {
+            "Opdavies\\Glassboxx\\Tests\\": "tests/"
+        }
+    },
+    "require-dev": {
+        "phpunit/phpunit": "^9.1"
+    }
 }

src/Glassboxx/Config.php

@@ -0,0 +1,40 @@
+<?php
+
+namespace Opdavies\Glassboxx;
+
+class Config
+{
+    /** @var int $vendorId */
+    private $vendorId;
+
+    /** @var string $username */
+    private $username;
+
+    /** @var string $password */
+    private $password;
+
+    public function __construct(
+		int $vendorId,
+        string $username,
+        string $password
+	) {
+        $this->password = $password;
+        $this->username = $username;
+        $this->vendorId = $vendorId;
+    }
+
+    public function getPassword(): string
+    {
+        return $this->password;
+    }
+
+    public function getUsername(): string
+    {
+        return $this->username;
+    }
+
+    public function getVendorId(): int
+    {
+        return $this->vendorId;
+    }
+}

tests/Glassboxx/ConfigTest.php

@@ -0,0 +1,22 @@
+<?php
+
+namespace Opdavies\Glassboxx\Tests\Glassboxx;
+
+use Opdavies\Glassboxx\Config;
+use PHPUnit\Framework\TestCase;
+
+class ConfigTest extends TestCase
+{
+    public function testThatGettersReturnExpectedValues(): void
+    {
+        $config = new Config(
+            12345,
+            'opdavies',
+            'secret'
+        );
+
+        $this->assertSame(12345, $config->getVendorId());
+        $this->assertSame('opdavies', $config->getUsername());
+        $this->assertSame('secret', $config->getPassword());
+    }
+}