chore(cargo): use tox from crates.io

Author: Roman Proskuryakov

Cargo.lock

@@ -24,7 +24,7 @@ itertools = "0.7"
 log = "0.4"
 tokio = "0.1.7"
 tokio-codec = "0.1"
-tox = { git = "https://github.com/tox-rs/tox" }
+tox = "<= 0.1"
 
 [target.'cfg(unix)'.dependencies]
 syslog = "4.0"