Update changelog to include 3.8.5 and 3.8.6 changes
# Unreleased
+- None
+
+# 3.8.6
+
+## Updated
+
+- `http_server_request_latency` to include HTTP method key
+
+# 3.8.5
+
+## Fixed
- Fixed plugin configuration not being validated
+
+## Updated
- Added stats and tracing support with opencensus
+## Removed
+- Tracing support via opentracing.io
+
# 3.8.4
## Fixed
