message: chore(dependencies): update to futures alpha 18
  Closes
diff: @@ -23,9 +23,9 @@ include = [
  [dependencies]
  bytes = "0.4.4"
  -futures-core-preview = { version = "0.3.0-alpha.17" }
  -futures-channel-preview = { version = "0.3.0-alpha.17" }
  -futures-util-preview = { version = "0.3.0-alpha.17" }
  +futures-core-preview = { version = "0.3.0-alpha.18" }
  +futures-channel-preview = { version = "0.3.0-alpha.18" }
  +futures-util-preview = { version = "0.3.0-alpha.18" }
  http = "0.1.15"
  http-body = "0.1"
  httparse = "1.0"
  @@ -37,7 +37,7 @@ net2 = { version = "0.2.32", optional = true }
  pin-utils = "0.1.0-alpha.4"
  time = "0.1"
  tokio = { version = "0.2.0-alpha.2", optional = true, default-features = false, features = ["rt-full"] }
  -tokio-buf = "0.2.0-alpha.1"
  +#tokio-buf = "0.2.0-alpha.1"
  tokio-executor = "0.2.0-alpha.2"
  tokio-io = "0.2.0-alpha.2"
  tokio-sync = "0.2.0-alpha.2"
  