Added change assignee and delete method

- Added a method to delete issues
- Added a mathod to update the assignee field, if the field is not in the edit dialog of the project (see https://docs.atlassian.com/jira/REST/cloud/#api/2/issue-editIssue - Quote: "If a field is not configured to appear on the edit screen, then it will not be in the editmeta, and a field validation error will occur if it is submitted; however connect add-on with admin scope are able to override the screen security."

Author: CobbleCity

src/Issue/IssueService.php

@@ -203,7 +203,44 @@ public function addComment($issueIdOrKey, $comment)
 
         return $comment;
     }
-
+    
+    /**
+	 * Change a issue assignee
+	 *
+	 * @param issueIdOrKey Issue id or key
+	 * @param assignee array of assigne field informations
+	 *
+	 */
+	public function changeAssignee($issueIdOrKey, $assignee)
+	{
+		$this->log->addInfo("changeAssignee=\n");
+
+		$data = json_encode($assignee);
+
+		$ret = $this->exec($this->uri."/$issueIdOrKey/assignee", $data, 'PUT');
+
+		$this->log->addInfo('change assignee of '.$issueIdOrKey.' to '.json_encode($assignee).' result='.var_export($ret, true));
+
+		return $ret;
+	}
+
+	/**
+	 * Delete a issue.
+	 *
+	 * @param issueIdOrKey Issue id or key
+	 *
+	 */
+	public function deleteIssue($issueIdOrKey)
+	{
+		$this->log->addInfo("deleteIssue=\n");
+
+		$ret = $this->exec($this->uri."/$issueIdOrKey", '', 'DELETE');
+
+		$this->log->addInfo('delete issue '.$issueIdOrKey.' result='.var_export($ret, true));
+
+		return $ret;
+	}
+    
     /**
      * Get a list of the transitions possible for this issue by the current user, along with fields that are required and their types.
      *