update changelog (#976)

Author: scjohns

CHANGELOG.md

@@ -12,6 +12,8 @@ All notable changes to `src-cli` are documented in this file.
 ## Unreleased
 
 ### Added
+- `src validate install` can check executor connections [#974](https://github.com/sourcegraph/src-cli/pull/974)
+- `src validate install` can send test SMTP message [#973](https://github.com/sourcegraph/src-cli/pull/973)
 
 ### Changed
 - Renamed `src repo {add|update|delete}-kvp` to `repo {add|update|delete}-metadata` [#972](https://github.com/sourcegraph/src-cli/pull/972)