CHANGELOG.md: Add entry for 2.5.0-rc.0

Signed-off-by: Frederic Branczyk <fbranczyk@gmail.com>

CHANGELOG.md

@@ -1,3 +1,31 @@
+## 2.5.0-rc.0 / 2018-10-24
+
+* [CHANGE] Marathon SD: Various changes to adapt to Marathon 1.5+. #4499
+* [CHANGE] Discovery: Split `prometheus_sd_discovered_targets` metric by scrape and notify (Alertmanager SD) as well as by section in the respective configuration. #4753
+* [FEATURE] Add OpenMetrics support for scraping (EXPERIMENTAL). #4700
+* [FEATURE] Add unit testing for rules. #4350
+* [FEATURE] Make maximum number of samples per query configurable via `--query.max-samples` flag. #4513
+* [FEATURE] Make maximum number of concurrent remote reads configurable via `--storage.remote.read-concurrent-limit` flag. #4656
+* [ENHANCEMENT] Support s390x platform for Linux. #4605
+* [ENHANCEMENT] API: Add `prometheus_api_remote_read_queries` metric tracking currently executed or waiting remote read API requests. #4699
+* [ENHANCEMENT] Remote Read: Add `prometheus_remote_storage_remote_read_queries` metric tracking currently in-flight remote read queries. #4677
+* [ENHANCEMENT] Remote Read: Reduced memory usage. #4655
+* [ENHANCEMENT] Discovery: Add `prometheus_sd_discovered_targets`, `prometheus_sd_received_updates_total`, `prometheus_sd_updates_delayed_total`, and `prometheus_sd_updates_total` metrics for discovery subsystem. #4667
+* [ENHANCEMENT] Discovery: Improve performance of previously slow updates of changes of targets. #4526
+* [ENHANCEMENT] Kubernetes SD: Add extended metrics. #4458
+* [ENHANCEMENT] OpenStack SD: Support discovering instances from all projects. #4682
+* [ENHANCEMENT] OpenStack SD: Discover all interfaces. #4649
+* [ENHANCEMENT] OpenStack SD: Support `tls_config` for the used HTTP client. #4654
+* [ENHANCEMENT] Triton SD: Add ability to filter triton_sd targets by pre-defined groups. #4701
+* [ENHANCEMENT] Web UI: Avoid browser spell-checking in expression field. #4728
+* [ENHANCEMENT] Web UI: Add scrape duration and last evaluation time in targets and rules pages. #4722
+* [ENHANCEMENT] Web UI: Improve rule view by wrapping lines. #4702
+* [ENHANCEMENT] Rules: Error out at load time for invalid templates, rather than at evaluation time. #4537
+* [ENHANCEMENT] TSDB: Add metrics for WAL operations. #4692
+* [BUGFIX] Change max/min over_time to handle NaNs properly. #4386
+* [BUGFIX] Check label name for `count_values` PromQL function. #4585
+* [BUGFIX] Ensure that vectors and matrices do not contain identical label-sets. #4589
+
 ## 2.4.3 / 2018-10-04
 
 * [BUGFIX] Fix panic when using custom EC2 API for SD #4672