refactor: move release notes into changelog

lib/workers/pr/changelog/index.js

 const versioning = require('../../../versioning');
-const { addReleaseNotes } = require('../release-notes');
+const { addReleaseNotes } = require('./release-notes');
 
 const sourceGithub = require('./source-github');
 

lib/workers/pr/release-notes.js → lib/workers/pr/changelog/release-notes.js

 const changelogFilenameRegex = require('changelog-filename-regex');
 const { linkify } = require('linkify-markdown');
 const MarkdownIt = require('markdown-it');
-const ghGot = require('../../platform/github/gh-got-wrapper');
+const ghGot = require('../../../platform/github/gh-got-wrapper');
 
 const markdown = new MarkdownIt('zero');
 markdown.enable(['heading', 'lheading']);

test/workers/pr/release-notes.spec.js

@@ -3,7 +3,7 @@ const ghGot = require('gh-got');
 const {
   getReleaseNotes,
   getReleaseNotesMd,
-} = require('../../../lib/workers/pr/release-notes');
+} = require('../../../lib/workers/pr/changelog/release-notes');
 
 const angularJsChangelogMd = fs.readFileSync(
   'test/_fixtures/changelog-md/angular.js.md',