Produce Dropwizard timer metrics instead of gauges in MetricsFilter

[lidkowiak]

Here spring-boot-dropwizard-metric-filter I implemented DropwizardMetricsFilter which produces timer metrics instead of only last response time. It is based on MetricsFilter and adds e.g. percentiles and rates metrics.

What do you think about merging it into Spring Boot Actuator? It could be enabled via AutoConfiguration when Dropwizard Metrics is on the classpath and/or with ConditionalOnProperty.