Exposing CA keys in a mine creates a security flaw, thus such
should be avoided.
This change removes code responsible for putting and retrieving
CA key from a mine and changes the ca.sls state to allow configuring
where CA cert and its key would be generated as well as their owners.

Fixes PROD-13439

Change-Id: I6d78b13dcb3754c51606edd7e2d8158e128244a4

This is useful when using proxies. The default Tornado backend does not
utilize proxy environment variables and isn't able to set no_proxy variable.

Change-Id: I4a51c6fc9abe65d46ed4f3adeb30f7a25337857e

Change-Id: I73a4a14734651f6483fae169a2290e9c5b377d76

Change-Id: Ic64656c6fc3d4f561226d884b8bfb535dd537e14

Change-Id: I2aba1213b1dda46aee929b8ea583c41316e3eb0b