Elois/cargo lock v2

lib/core/core/Cargo.toml

@@ -25,7 +25,7 @@ durs-network = { path = "../network" }
 durs-network-documents = { path = "../../dunp/network-documents" }
 envy = "0.4.1"
 failure = "0.1.5"
-fern = { version = "0.5.8", features = ["colored"] }
+fern = { version = "0.6.0", features = ["colored"] }
 log = "0.4.*"
 serde = "1.0.*"
 serde_derive = "1.0.*"