add scripts to generate release note automatically.
Fix python style issue.
Merge pull request #33 from lyhypacm/scripts-enhancement

add scripts to generate release note automatically.
create AbstractFileUploadService and make PictureService extends from it.
add ZipService class and service method about upload contest ZIP archive.
move uploadFile method to utils.
Merge pull request #34 from pfctgeorge/contest-management

refactor service about file upload and add ZipService
[UPDATE] Add contest rank list

Change-Id: I13bcab59d40721b82cb1cd88374d8994d9a3310d
[UPDATE] Compile grunt project

Change-Id: Ieed59c85fa6051084978caf8e798aa5f9536495a