Fix token renewal for expired token (issue #21)
The issue described in #21 (closed) is bug. When token is too old the renewal never happens as it raise self.grant.refresh_token
an error before it reaches self.refresh_if_needed
.
In current MR, the call to self.grant.refresh_token
is delegated to self.refresh_if_needed
instead of being called within self.get_access_token
.