Update doRefreshAccessTokenRequest to pass in client ID

[dymurray]

Without this the following code fails:

var mbclient = new MoneyButtonClient(OAUTH_ID)
mbclient.setRefreshToken(refreshToken)
mbclient.getValidAccessToken()

With Unexpected Token Type which is a red herring, the actual error comes from a 400 bad request since the client ID isn't specified in the token request.

[calvogenerico]

I'm reviewing this now.