Process images

[MrOrz]

Fixes #287

• Upgrade media-manager to 0.1.0
• Implement image processors
• Allow users to get ORIGINAL, PREVIEW, THUMBNAIL variants
  • Doc: https://g0v.hackmd.io/@mrorz/cofacts-media-manager#Extended-goal-supporting-signed-URLs-and-preview-URLs
  • PREVIEW: fixed-width downsized image for website detail page, webp
  • THUMBNAIL: fixed-height downsized image for chatbot & website list page, jpg
  • ORIGINAL: Only for logged-in website users
• All media urls are signed URL with 1-day duration
• Add integration test with GCS & media-manager

[coveralls]

Coverage increased (+0.06%) to 87.608% when pulling 950f39978f5d88f7b5d3222b46b145bb4b529971 on process-image into f5e6992fbe65dda7214eeaeaf05f025f2d440b8e on master.