Add changelog

Signed-off-by: Daniel González Lopes <danielgonzalezlopes@gmail.com>

CHANGELOG.md

@@ -3,3 +3,4 @@
 * [CHANGE] Bloom filters are now sharded to reduce size and improve caching, as blocks grow. This is a **breaking change** and all data stored before this change will **not** be queryable. [192](https://github.com/grafana/tempo/pull/192)
 * [ENHANCEMENT] CI checks for vendored dependencies using `make vendor-check`. Update CONTRIBUTING.md to reflect the same before checking in files in a PR. [#274](https://github.com/grafana/tempo/pull/274)
 * [ENHANCEMENT] Add warnings for suspect configs. [#294](https://github.com/grafana/tempo/pull/294)
+* [BUGFIX] Prune in-memory blocks from missing tenants. [#314](https://github.com/grafana/tempo/pull/314)