- add issue's changelog mapping class (History, ChangeLog)

-  resource expansion (fixed #145)

src/Issue/ChangeLog.php

@@ -0,0 +1,30 @@
+<?php
+
+namespace JiraRestApi\Issue;
+
+/**
+ * Issue ChangeLog
+ *
+ * Class ChangeLog
+ *
+ * @package JiraRestApi\Issue
+ */
+class ChangeLog implements \JsonSerializable
+{
+    /** @var integer */
+    public $startAt;
+
+    /** @var integer */
+    public $maxResults;
+
+    /** @var integer */
+    public $total;
+
+    /** @var History[]|null */
+    public $histories;
+
+    public function jsonSerialize()
+    {
+        return array_filter(get_object_vars($this));
+    }
+}

src/Issue/History.php

@@ -0,0 +1,30 @@
+<?php
+
+namespace JiraRestApi\Issue;
+
+/**
+ * ChangeLog History
+ *
+ * Class History
+ *
+ * @package JiraRestApi\Issue
+ */
+class History implements \JsonSerializable
+{
+    /** @var integer */
+    public $id;
+
+    /** @var Reporter */
+    public $author;
+
+    /** @var string */
+    public $created;
+
+    /** @var array|null */
+    public $items;
+
+    public function jsonSerialize()
+    {
+        return array_filter(get_object_vars($this));
+    }
+}

src/Issue/Issue.php

@@ -23,6 +23,27 @@ class Issue implements \JsonSerializable
     /** @var IssueField */
     public $fields;
 
+    /** @var array|null */
+    public $renderedFields;
+
+    /** @var array|null */
+    public $names;
+
+    /** @var array|null */
+    public $schema;
+
+    /** @var array|null */
+    public $transitions;
+
+    /** @var array|null */
+    public $operations;
+
+    /** @var array|null */
+    public $editmeta;
+
+    /** @var ChangeLog|null */
+    public $changelog;
+
     public function jsonSerialize()
     {
         return array_filter(get_object_vars($this));