Added vendor/ directory for Composer's installed files

vendor/alexgarrett/violin/src/Contracts/RuleContract.php

@@ -0,0 +1,33 @@
+<?php
+
+namespace Violin\Contracts;
+
+interface RuleContract
+{
+    /**
+     * Runs the rule to check validity. Returning false fails
+     * the check and returning true passes the check.
+     *
+     * @param  mixed $value
+     * @param  array $input
+     * @param  array $args
+     *
+     * @return bool
+     */
+    public function run($value, $input, $args);
+
+    /**
+     * The error given if the rule fails.
+     *
+     * @return string
+     */
+    public function error();
+
+    /**
+     * If the rule can be skipped, if the value given
+     * to the validator is not required.
+     *
+     * @return [type] [description]
+     */
+    public function canSkip();
+}