Update handlebars to 3.0.1

Updating handlebars v2.0.1 -> v3.0.1
Removing hashbrown v0.5.0
Updating quick-error v1.2.2 -> v1.2.3
Removing same-file v1.0.5
Removing walkdir v2.2.9

Author: JohnTitor

Cargo.lock

@@ -82,7 +82,7 @@ tokio = { version = "0.2", default-features = false, features = ["net", "signal"
 hyper = "0.13"
 ctrlc = { version = "3.0", features = ["termination"] }
 indexmap = "1.0.2"
-handlebars = "2.0.1"
+handlebars = "3.0.1"
 
 [dev-dependencies]
 conduit-test = "0.8"