have readme use Istio Services UI element instead of CLI for binding
have readme use Istio Services UI element instead of CLI for binding

Change-Id: I40729030605dff581ff4408d04f6bf4bd26bba5f

apigee/istio-mixer-adapter,apigee/istio-mixer-adapter,apigee/istio-mixer-adapter,apigee/istio-mixer-adapter