Add interface for APIBaseClient

Problem:
There are three clients based off the APIBaseClient so three code paths
are needed to make the same type of call in each client

Solution:
Add an interface so any client that satisfies it can be used to make
these calls

clientbase/ops.go

@@ -12,6 +12,12 @@ import (
 	"github.com/rancher/norman/types"
 )
 
+type APIOperations struct {
+	Opts   *ClientOpts
+	Types  map[string]types.Schema
+	Client *http.Client
+}
+
 func (a *APIOperations) setupRequest(req *http.Request) {
 	req.Header.Add("Authorization", a.Opts.getAuthHeader())
 }