v0.3.8

Fixes a deadlock in InMemSink. #124

v0.3.7

Fix behaviour with pre-defined Prometheus metrics where we would reset Gauges and invalidate Summaries after Expiry despite them being pre-declared as always useful values. See #123 for more details.

v0.3.6

Fixes an issue in Prometheus sink where dynamic labels cause changes to the help message/description which Prometheus doesn't like.