Provide `salt-api`'s configuration defaults. Refs #52.

We now override the necessary keys to adapt the salt-master default configuration to salt-api and feed that to `salt.config.master_config`.
There no need to do our own `include` code since that's also done in `salt.config.master_config`.
Merge pull request #53 from s0undt3ch/issues/52

Provide `salt-api`'s configuration defaults. Refs #52.