Update polling v0.1.5

Author: Stjepan Glavina

Cargo.toml

@@ -19,7 +19,7 @@ futures-lite = "0.1.10"
 libc = "0.2.74"
 once_cell = "1.4.0"
 parking = "2.0.0"
-polling = { git = "https://github.com/stjepang/polling.git", branch = "timeout-test" }
+polling = "0.1.5"
 socket2 = { version = "0.3.12", features = ["pair", "unix"] }
 vec-arena = "0.5.0"