Bump failure from 0.1.5 to 0.1.6

Bumps [failure](https://github.com/rust-lang-nursery/failure) from 0.1.5 to 0.1.6.
- [Release notes](https://github.com/rust-lang-nursery/failure/releases)
- [Changelog](https://github.com/rust-lang-nursery/failure/blob/master/RELEASES.md)
- [Commits](https://github.com/rust-lang-nursery/failure/commits)

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

Author: dependabot-preview[bot]

Cargo.lock

@@ -7,7 +7,7 @@ edition = '2018'
 [dependencies]
 clap = "2.25"
 env_logger = "0.7"
-failure = "0.1.1"
+failure = "0.1.6"
 log = "0.4"
 serde = { version = "1", features = ["derive"] }
 serde_json = "1"