Comment 5 for bug 1802407

So having done some preliminary work around adding ssl_ca functionality to the charm, the following areas need to be covered:

1. Adding the ssl_* options to the glance-simple-streams charm
2. Modifying the gss charm to actually use the values
3. Adding tests to the gss charm to ensure that the contract around ssl_* options is maintained over time.
4. Changing simplestreams python package to use SSL endpoints; at present it is unaware of certs, etc.

Thus to provide this feature, both simplestreams and the gss charm need to be modified.