build(deps): bump futures from 0.3.5 to 0.3.6

Bumps [futures](https://github.com/rust-lang/futures-rs) from 0.3.5 to 0.3.6.
- [Release notes](https://github.com/rust-lang/futures-rs/releases)
- [Changelog](https://github.com/rust-lang/futures-rs/blob/master/CHANGELOG.md)
- [Commits](https://github.com/rust-lang/futures-rs/compare/0.3.5...0.3.6)

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

Cargo.lock

@@ -389,9 +389,9 @@ checksum = "3dcaa9ae7725d12cdb85b3ad99a434db70b468c09ded17e012d86b5c1010f7a7"
 
 [[package]]
 name = "futures"
-version = "0.3.5"
+version = "0.3.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "1e05b85ec287aac0dc34db7d4a569323df697f9c55b99b15d6b4ef8cde49f613"
+checksum = "5d8e3078b7b2a8a671cb7a3d17b4760e4181ea243227776ba83fd043b4ca034e"
 dependencies = [
  "futures-channel",
  "futures-core",
@@ -420,9 +420,9 @@ checksum = "d674eaa0056896d5ada519900dbf97ead2e46a7b6621e8160d79e2f2e1e2784b"
 
 [[package]]
 name = "futures-executor"
-version = "0.3.5"
+version = "0.3.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "10d6bb888be1153d3abeb9006b11b02cf5e9b209fda28693c31ae1e4e012e314"
+checksum = "cc709ca1da6f66143b8c9bec8e6260181869893714e9b5a490b169b0414144ab"
 dependencies = [
  "futures-core",
  "futures-task",
@@ -464,9 +464,9 @@ dependencies = [
 
 [[package]]
 name = "futures-util"
-version = "0.3.5"
+version = "0.3.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "8764574ff08b701a084482c3c7031349104b07ac897393010494beaa18ce32c6"
+checksum = "8a894a0acddba51a2d49a6f4263b1e64b8c579ece8af50fa86503d52cd1eea34"
 dependencies = [
  "futures-channel",
  "futures-core",