Bump structopt from 0.3.5 to 0.3.6 (#20)

Bumps [structopt](https://github.com/TeXitoi/structopt) from 0.3.5 to 0.3.6.
- [Release notes](https://github.com/TeXitoi/structopt/releases)
- [Changelog](https://github.com/TeXitoi/structopt/blob/master/CHANGELOG.md)
- [Commits](TeXitoi/structopt@v0.3.5...v0.3.6)

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

Author: dependabot-preview[bot]

Cargo.lock

@@ -14,7 +14,7 @@ exclude = [
 ]
 
 [dependencies]
-structopt = "0.3.5"
+structopt = "0.3.6"
 human-panic = "1.0.1"
 image = "0.22.3"