refactor: fix lint on lib/response.js

Signed-off-by: BoHong Li <raccoon@hackmd.io>

lib/response.js

@@ -501,17 +501,17 @@ function githubActionGist (req, res, note) {
           var title = models.Note.decodeTitle(note.title)
           var filename = title.replace('/', ' ') + '.md'
           var gist = {
-            'files': {}
+            files: {}
           }
           gist.files[filename] = {
-            'content': content
+            content: content
           }
           var gistUrl = 'https://api.github.com/gists'
           request({
             url: gistUrl,
             headers: {
               'User-Agent': 'CodiMD',
-              'Authorization': 'token ' + accessToken
+              Authorization: 'token ' + accessToken
             },
             method: 'POST',
             json: gist