* Make metallb image repos configurable
* Moved metallb image repo definitions to download role defaults
* Removed comment. These are set in download defaults
* Option for MetalLB to talk BGP
* Check for BGP peers when metallb_protocol is bgp
* README clarification
* Commented values as documentation only in the sample inventory
* layer 2 or BGP, not both
This changes MetalLB contrib to one of addons for deploying MetalLB with
Kubernetes cluster deployment. By the default, Kubespray doesn't deploy
MetalLB addon.