Bump chrono from 0.4.6 to 0.4.7 (#4812)

Bumps [chrono](https://github.com/chronotope/chrono) from 0.4.6 to 0.4.7.
- [Release notes](https://github.com/chronotope/chrono/releases)
- [Changelog](https://github.com/chronotope/chrono/blob/master/CHANGELOG.md)
- [Commits](https://github.com/chronotope/chrono/compare/v0.4.6...v0.4.7)

Signed-off-by: dependabot-preview[bot] <support@dependabot.com>

kvstore/Cargo.toml

@@ -11,7 +11,7 @@ edition = "2018"
 [dependencies]
 bincode = "1.1.4"
 byteorder = "1.3.2"
-chrono = "0.4.0"
+chrono = "0.4.7"
 crc = "1.8.1"
 memmap = "0.7.0"
 rand = "0.6.5"