chore(dependencies): remove tokio-executor from runtime feature

Author: seanmonstar

Cargo.toml

@@ -38,7 +38,7 @@ pin-utils = "0.1.0-alpha.4"
 time = "0.1"
 tokio = { git = "https://github.com/tokio-rs/tokio", optional = true, default-features = false, features = ["rt-full"] }
 tokio-buf = "0.1"
-tokio-executor = { git = "https://github.com/tokio-rs/tokio", optional = true }
+tokio-executor = { git = "https://github.com/tokio-rs/tokio" }
 tokio-io = { git = "https://github.com/tokio-rs/tokio" }
 tokio-reactor = { git = "https://github.com/tokio-rs/tokio", optional = true }
 tokio-sync = { git = "https://github.com/tokio-rs/tokio" }
@@ -70,7 +70,6 @@ default = [
 runtime = [
     "net2",
     "tokio",
-    "tokio-executor",
     "tokio-reactor",
     "tokio-tcp",
     "tokio-threadpool",