This adds support for validation of ssl certs returned by remote
servers over SSL. The --ca-file param represents the CA cert used
to sign the remote server's cert. Use --insecure if the remote
server is using a self-signed cert or you don't have the CA cert.
Related to bp glance-client-parity
Change-Id: I45253a6e2d88da599addfcc464571e62ae920166