Deploy to AWS using AWS SAM and Lambda

Important Changes

• Format the message at the start in HTML in #9.
• Deploy to AWS using AWS SAM CLI in #11.
• Fix version of urllib3 and download DB file if not exists in #14.
• Add step to set WebHook of bot.
• Not query DB for now, since its dir is read only.

Full Changelog: v0.1...v0.2