Add debug log for get_token.
Add debug log for get_token.

bingosummer/bosh-azure-cpi-release,bingosummer/bosh-azure-cpi-release,gossion/bosh-azure-cpi-release,cloudfoundry-incubator/bosh-azure-cpi-release,AbelHu/bosh-azure-cpi-release,gossion/bosh-azure-cpi-release,cloudfoundry-incubator/bosh-azure-cpi-release,AbelHu/bosh-azure-cpi-release,gossion/bosh-azure-cpi-release,AbelHu/bosh-azure-cpi-release,cloudfoundry-incubator/bosh-azure-cpi-release,bingosummer/bosh-azure-cpi-release