Split Key class initialization

@thatch45, [this](https://github.com/s0undt3ch/salt/commit/f0db1759c09e0678d70f9a04bc03007c4b1e4b44) was the breakage.

If it really makes no sense to you to separate these, close this PR and I'll tell PyLint to ignore the fact that we're not calling our parent class.