[Rest Client] Use options for client.New (#463)

* adding in clientopts to the rest client

Signed-off-by: Corey Aloia <corey.aloia@sap.com>

pkg/rest/client/apiv1_client_opts.go

@@ -0,0 +1,38 @@
+package client
+
+import (
+	"net/http"
+	"time"
+)
+
+// options is a struct that holds the options for the rest client
+type options struct {
+	transport http.RoundTripper
+	timeout   time.Duration
+}
+
+type Option interface {
+	apply(*options)
+}
+
+func getDefaultOptions() *options {
+	return &options{
+		timeout: 30 * time.Second,
+	}
+}
+
+type transportOption struct {
+	transport http.RoundTripper
+}
+
+func (t transportOption) apply(opts *options) {
+	opts.transport = t.transport
+}
+
+// WithOptTransport sets the transport for the rest client.
+// Transport specifies the mechanism by which individual
+// HTTP requests are made.
+// If nil, http.DefaultTransport is used.
+func WithOptTransport(transport http.RoundTripper) Option {
+	return transportOption{transport}
+}