Bump env_logger from 0.6.2 to 0.7.1 (#230)

Bumps [env_logger](https://github.com/sebasmagri/env_logger) from 0.6.2 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@v0.6.2...v0.7.1)

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

Author: dependabot-preview[bot]

Cargo.lock

@@ -14,6 +14,6 @@ serde_derive = "1.0"
 tokio-core = "0.1.8"
 docopt = "1.0"
 log = "0.4"
-env_logger = "0.6"
+env_logger = "0.7"
 futures = "0.1.14"
 web3 = { git = "https://github.com/tomusdrw/rust-web3" }

cli/Cargo.toml

@@ -14,6 +14,6 @@ serde_derive = "1.0"
 tokio-core = "0.1.8"
 docopt = "1.0"
 log = "0.4"
-env_logger = "0.6"
+env_logger = "0.7"
 futures = "0.1.14"
 web3 = { git = "https://github.com/tomusdrw/rust-web3" }