Create setup script

[brettstack]

Currently, developers need to clone the repo and perform search-replace to get started.

The first version of the setup script should allow users to define a new application name and perform this replacement for them.

The developer experience should be:

1. git clone
2. npm i
3. npm run setup -- --appName=MyNewApplication

[brettstack]

I forgot the requirement for setting up the credentials. What do you think about instead of passing in parameters like this, we have a config file like setup.config.json:

{
  "applicationName": "",
  "shortApplicationName": "",
  "awsProfiles": {
    "dev": {
      "accessKey": "",
      "secretAccessKey": ""
    },
    "staging": {
      "accessKey": "",
      "secretAccessKey": ""
    },
    "prod": {
      "accessKey": "",
      "secretAccessKey": ""
    }
  }
}