Make Variable Updates Optional or Secure

[danielshiplett]

Currently, when you already have your Lambda deployed, and you re-upload it with lambda-uploader, it will replace all environment variables with whatever is configured in the lambda.json file or specified with the --variables option. If neither are specified, it will remove all environment variables from the Lambda.

Could you add an option like --no-variables to avoid any variable update/delete? Or if this feature already exists and I'm just not seeing it, please provide documentation.

One other option, that actually solves my use case, is to allow an 'variables-file' field in the JSON that pulls the desired variables from another file location. This is specifically to allow me to specify secure variables that I want to avoid checking into Git. Again, if this feature already exists and I'm just missing it, please document.

Python: 2.7.15
lambda-uploader: 1.3.0