Bump env_logger from 0.6.1 to 0.7.1

Bumps [env_logger](https://github.com/sebasmagri/env_logger) from 0.6.1 to 0.7.1.
- [Release notes](https://github.com/sebasmagri/env_logger/releases)
- [Changelog](https://github.com/sebasmagri/env_logger/blob/master/CHANGELOG.md)
- [Commits](rust-cli/env_logger@v0.6.1...v0.7.1)

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

Author: dependabot-preview[bot]

Cargo.lock

@@ -26,7 +26,7 @@ protobuf-codegen = "2.3.0"
 byteorder = "1.0.0"
 bytes = "0.4"
 either = "1.5.3"
-env_logger = "0.6"
+env_logger = "0.7"
 fnv = "1.0.6"
 futures = "0.1"
 getopts = "0.2"