methods
- get_openrc
 - 
Given variable name, get OS_<uppercase variable name> from hashref
data.Use default from OPENRC_DEFAULT, if none exists. If none exists, and no default and in OPENRC_REQUIRED, report error.
 - login
 - 
Login and obtain token for further authentication.
Options:
 - services_from_catalog
 - 
Parse the catalog arrayref, and build up the services attribute