Updating 4.x client to expect query string params as ['params']

[douglasmiller]

This is an update for the 4.x version of the client.

This updates how optional parameters are specified in operations. In the 3.x version of the client, optional parameters were specified an optional keyword arguments directly on each operation. This 4.x update moves these parameters into a hash whose key, :params is an optional keyword argument on the operation.

This is to facilitate additional options that may be passed into each operation (e.g. :headers for custom headers).

The ability to specify custom headers was added to the 3.x clients in #597, though this solution is not very future flexible.

Existing 3.x code sample:

options = {
  limit: 200,
  headers: {
    'Accept-Language' => 'fr'
  }
}
accounts = @client.list_accounts(options)

Updated 4.x code sample:

options = {
  params: {
      limit: 200
  }
  headers: {
    'Accept-Language' => 'fr'
  }
}
accounts = @client.list_accounts(options)