Bump version of prometheus-to-sd to 0.2.3.
Bump version of prometheus-to-sd to 0.2.3.

kawych/k8s-stackdriver,GoogleCloudPlatform/k8s-stackdriver,GoogleCloudPlatform/k8s-stackdriver,kawych/k8s-stackdriver,kawych/k8s-stackdriver,kawych/k8s-stackdriver,GoogleCloudPlatform/k8s-stackdriver