feat(auth): Add scope support

[statianzo]

Adds support for specifying scope when creating Domo SDK client. scope is a list of scope names such as ["data", "user", "account"].

This allows limiting the scope of access tokens to a subset of the scopes granted on the API client. Not specifying scope maintains the default behavior of access tokens having the same scopes as the API client.

Example

domo = Domo('client-id','secret',api_host='api.domo.com', scope=['data'])
domo.ds_get('2f09a073-54a4-4269-8c62-b776e67d59f0') # works

domo.users.get(123) # fails, no "user" scope

[statianzo]

@jeremydmorris

[Falcc]

I do not see anything concerning, and your confirmation of backwards compatibility should scope not be specified is appropriate.