Add configuration interface

Author: Jaspaul

src/Configurations/Configuration.php

@@ -0,0 +1,35 @@
+<?php
+
+namespace SoapBox\SignedRequests\Configurations;
+
+interface Configuration
+{
+    /**
+     * Returns the name of the header that will contain the algorithm used to
+     * sign the request.
+     *
+     * @return string
+     */
+    public function getAlgorithmHeader(): string;
+
+    /**
+     * Returns the name of the header that will contain the generated signature.
+     *
+     * @return string
+     */
+    public function getSignatureHeader(): string;
+
+    /**
+     * Returns the algorithm to use to generate the signature.
+     *
+     * @return string
+     */
+    public function getSigningAlgorithm(): string;
+
+    /**
+     * Returns the key to sign the request with.
+     *
+     * @return string
+     */
+    public function getSigningKey(): string;
+}