Merge branch '1791-fix-github-issue-order' into 'master'

Fix wrong order of issues when importing from github

### 1. What does this MR do?

The order of issues imported from GitHub is fixed.

### 2. Are there points in the code the reviewer needs to double check?

Nothing.

### 3. Why was this MR needed?

The default behaviors of GitHub API at listing issues are sort: :created and direction: :desc.

See GitHub API details at https://developer.github.com/v3/issues/#list-issues.

### 4. What are the relevant issue numbers / Feature requests?

Fixes #1791

### 5. Screenshots (if relevant)

Nothing

See merge request !898

CHANGELOG

 Please view this file on the master branch, on stable branches it's out of date.
 
 v 7.13.0 (unreleased)
+  - Fix order of issues imported form GitHub (Hiroyuki Sato)
   - Fix Merge Request webhook to properly fire "merge" action when accepted from the web UI
   - Add `two_factor_enabled` field to admin user API (Stan Hu)
   - Fix invalid timestamps in RSS feeds (Rowan Wookey)

lib/gitlab/github_import/importer.rb

@@ -11,7 +11,9 @@ module Gitlab
 
       def execute
         #Issues && Comments
-        client.list_issues(project.import_source, state: :all).each do |issue|
+        client.list_issues(project.import_source, state: :all,
+                                                  sort: :created,
+                                                  direction: :asc).each do |issue|
           if issue.pull_request.nil?
 
             body = @formatter.author_line(issue.user.login, issue.body)