Add framework for remote liveness check

internal/remotes/remotes.go

@@ -21,6 +21,15 @@ func (r *Remotes) AddRemote(remote remote.Remote) {
 	*r = append(*r, remote)
 }
 
+func (r *Remotes) GetRemoteByHost(host string) remote.Remote {
+	for _, remote := range *r {
+		if remote.GetInfo().Host == host {
+			return remote
+		}
+	}
+	return nil
+}
+
 // Launches project streamsers for all remotes in goroutines
 // returns slice of load.ProgressInfo
 func (r *Remotes) StreamRemotes(opts *remote.RemoteQueryOpts) []*load.ProgressInfo {