Switch to PSR-4, fix CS and update service provider

src/Matchers/InStringMatcher.php

@@ -0,0 +1,28 @@
+<?php
+
+namespace TomLingham\Searchy\Matchers;
+
+/**
+ * Matches against any occurrences of a string within a string and is case-insensitive.
+ *
+ * For example, a search for 'smi' would match; 'John Smith' or 'Smiley Face'
+ *
+ * Class InStringMatcher
+ */
+class InStringMatcher extends BaseMatcher
+{
+    /**
+     * @var string
+     */
+    protected $operator = 'LIKE';
+
+    /**
+     * @param $searchString
+     *
+     * @return string
+     */
+    public function formatSearchString($searchString)
+    {
+        return "%$searchString%";
+    }
+}