Have separate URL for latest commit on master

[jpike88]

So you and I don't have to wait for a release to take advantage of the latest commit, and this template must be based in S3, it's probably worth having another 'Create Stack' button that allows people to use a template based on the latest commit (like a 'beta' button or something). That way people are less likely to feel the need to fork or do something manual.

[ks888]

Yes, I also think it's better to have a button to try out latest commits. To do that, we have at least these TODOs:

• Upload a latest cloud formation template to S3 bucket. As you said, the template has to be based in S3.
• Build & upload the binaries of lambda functions to S3 bucket. If a lambda function are modified by a commit, its binaries also have to be updated.
• Build & upload the frontend code to S3 bucket just like lambda functions.
• Let a CI service automatically do these tasks on latest commits. The repository currently uses wercker for testing, but it seems the service doesn't have a feature to hide AWS credentials to upload things. So we need other CI service for this.

Though it's not as easy as a 'Create Stack' button, this doc describes how to try out latest commit for now.