[Feature Request] Add the ability to specify a custom Certificate Authority to be used when cloning git repos for schemas

[markafarrell]

Issue

Currently if your schema is stored in a git repository that has a Self Signed certificate in its certificate chain, then there is no way to use that schema with SDC

Proposed Solution

Add an addtional parameter ca to the Schema CRD (spec.repositories[].ca) that will point to a secret of type kubernetes.io/tls where the Custom CA certificate is stored in the tls.crt key.

[steiler]

We should probably also add an insecure flag that allows for skipping verification of the server’s TLS certificate chain.