Update README for Prometheus change
Platform 1.89
+* Reporting
+
+ ReportingPrometheusModule() no longer reports metrics using the Prometheus
+ "counter" or "summary" types. All metrics are now reported as the Prometheus
+ "gauge" type using names and values as close as possible to the way they
+ are reported to KairosDB. This means that counts are reported as one-minute
+ buckets, not total since startup.
+
* Trace tokens
Trace token properties with keys starting with "_" are now no longer
