Fixing AzureCLI / CloudShell authentication
Fixing AzureCLI / CloudShell authentication

 - Hard-coding the value for `expiresIn` due to the Azure CLI and CloudShell authentication models having different types
 - Updating `expiresOn` to be the difference in seconds between the baseDate & now - rather than a date
 - Parsing the AzureCLI time out in the local system timezone, given it's saved in local time but with no timezone info

Azure/go-autorest