WIP: OAS-19: Add base node cli

[facundovictor]

This PR includes:

• base cli structure with automated help and parameters recognition.
• AWS credentials support + AWS env var support + option for specifying AWS profile + options for passing JSON config file.
• npm-shrinkwrap to start locking dependencies (for if the CLI is published to npm in the future).

Next thing to add:

• --init should create a bucket if does not exist and should upload the templates.
• --apply should try creating the stack if it does not exist or update it using the templates stored in s3

We need to decide:

• Are we going to include the CF templates inside the CLI package?
• How much flexibility we should offer in terms of modifying the CF templates?
• Need to decide the best way to pass the Stack parameters.

[grgur]

MIT

[grgur]

I suggest moving all env declarations at the top so it's clearer which env vars are needed

const {
  // AWS Access Key
  AWS_ACCESS_KEY_ID,

  // AWS secret key
  AWS_SECRET_ACCESS_KEY,

  // AWS profile name
  AWS_PROFILE,
} = process.env;

[grgur]

Which version of node do you use? I like that you added npm shrinkwrap, but maybe it's easier for development (at this point) to use package-lock.json.

@facundovictor this is an excellent PR here!

[facundovictor]

Thanks @grgur , I'll apply the changes and add the node version into the package.json.
I'm using Docker for developing and installing the dependencies. If you agree I could add that portion and update the README file.

I used latest node v10.8.0, though, we should try setting up tests with mocha and different docker images with different node versions.