[WIP] NewWithPasswordCredentials/NewWithClientCredentials return wrapper struct with .Token()

[drnic]

See example: https://github.com/starkandwayne/ultimate-guide-to-uaa-examples/blob/e8ca806baadb7907a91ca32ade13246c61bbdcbc/golang/resource-server-cli/src/resource-server-cli/main.go#L54-L66

With consideration to #5 proposal to change API#AuthenticatedClient into a function, perhaps API can become an interface with AuthenticatedClient rather than a struct; and the returned struct from NewWithXYZ can hold the xyz.Config and have its own AuthenticatedClient functions etc.

[jghiloni]

I see no problems with this but I'll wait for @joefitzgerald to get back from his vacation to look at it, as he's been working with the UAA team on this and may have to take this into account.

[joefitzgerald]

This is fixed in v0.2.0, which includes a uaa.API.Token function.