Increace tracing-tree version from 0.1.3 to 0.1.4

Author: Bram van den Heuvel

crates/ra_hir_ty/Cargo.toml

@@ -37,4 +37,4 @@ expect = { path = "../expect" }
 
 tracing = "0.1"
 tracing-subscriber = { version = "0.2", default-features = false, features = ["env-filter", "registry"] }
-tracing-tree = { version = "0.1.3" }
+tracing-tree = { version = "0.1.4" }