message: Use QueryParamIsTruthy in Tiller Proxy
diff: @@ -283,10 +283,7 @@ func (h *TillerProxy) DeleteRelease(w http.ResponseWriter, req *http.Request, pa
  return
  }
  }
  - purge := false
  - if req.URL.Query().Get("purge") == "1" || req.URL.Query().Get("purge") == "true" {
  - purge = true
  - }
  + purge := handlerutil.QueryParamIsTruthy("purge", req)
  err := h.ProxyClient.DeleteRelease(params["releaseName"], params["namespace"], purge)
  if err != nil {
  response.NewErrorResponse(handlerutil.ErrorCode(err), err.Error()).Write(w)
  