chore(deps): bump futures from 0.1.27 to 0.1.28

Bumps [futures](https://github.com/rust-lang-nursery/futures-rs) from 0.1.27 to 0.1.28.
- [Release notes](https://github.com/rust-lang-nursery/futures-rs/releases)
- [Changelog](https://github.com/rust-lang-nursery/futures-rs/blob/master/CHANGELOG.md)
- [Commits](https://github.com/rust-lang-nursery/futures-rs/compare/0.1.27...0.1.28)

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

Cargo.toml

@@ -19,7 +19,7 @@ maintenance = { status = "actively-developed" }
 actix-web= "0.7.19"
 actix= "0.7.9"
 askama = { version = "0.8.0", features= ["with-actix-web"] }
-futures = "0.1.27"
+futures = "0.1.28"
 libc = "0.2.58"
 log = "0.4.6"
 pretty_env_logger = "0.3.0"