build(deps): bump futures from 0.1.31 to 0.3.26

Bumps [futures](https://github.com/rust-lang/futures-rs) from 0.1.31 to 0.3.26.
- [Release notes](https://github.com/rust-lang/futures-rs/releases)
- [Changelog](https://github.com/rust-lang/futures-rs/blob/master/CHANGELOG.md)
- [Commits](rust-lang/futures-rs@0.1.31...0.3.26)

---
updated-dependencies:
- dependency-name: futures
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

Cargo.lock

@@ -36,7 +36,7 @@ elementtree = "1.2"
 failure = "0.1.2"
 filetime = "0.2"
 flate2 = "1.0"
-futures = "0.1"
+futures = "0.3"
 futures3 = { package = "futures", version = "0.3", features = ["compat"] }
 futures-fs = "0.0"
 futures-locks = "0.3"