chore(deps): bump structopt from 0.3.14 to 0.3.15

Bumps [structopt](https://github.com/TeXitoi/structopt) from 0.3.14 to 0.3.15.
- [Release notes](https://github.com/TeXitoi/structopt/releases)
- [Changelog](https://github.com/TeXitoi/structopt/blob/master/CHANGELOG.md)
- [Commits](https://github.com/TeXitoi/structopt/compare/v0.3.14...v0.3.15)

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

Cargo.lock

@@ -849,9 +849,9 @@ checksum = "6446ced80d6c486436db5c078dde11a9f73d42b57fb273121e160b84f63d894c"
 
 [[package]]
 name = "structopt"
-version = "0.3.14"
+version = "0.3.15"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "863246aaf5ddd0d6928dfeb1a9ca65f505599e4e1b399935ef7e75107516b4ef"
+checksum = "de2f5e239ee807089b62adce73e48c625e0ed80df02c7ab3f068f5db5281065c"
 dependencies = [
  "clap",
  "lazy_static",
@@ -860,9 +860,9 @@ dependencies = [
 
 [[package]]
 name = "structopt-derive"
-version = "0.4.7"
+version = "0.4.8"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "d239ca4b13aee7a2142e6795cbd69e457665ff8037aed33b3effdc430d2f927a"
+checksum = "510413f9de616762a4fbeab62509bf15c729603b72d7cd71280fbca431b1c118"
 dependencies = [
  "heck",
  "proc-macro-error",