Revert "Change com.force.sdk.oauth.connector.ForceOAuthConnector.getAccessToken to use refresh_token grant_type because com.force.sdk.oauth.connector.ForceOAuthConnector.createTokenInternal is expecting it to be not null."

This reverts commit 696716bf53f21d2b7a0208125ac3789db8c47f25.
Set OAuth authorization scope to include api and refresh_token

Fixes #28