remove walkdir from lib via handlebars

Cargo.lock

@@ -1,3 +1,5 @@
+# This file is automatically @generated by Cargo.
+# It is not intended for manual editing.
 [[package]]
 name = "aho-corasick"
 version = "0.6.8"
@@ -285,7 +287,6 @@ dependencies = [
  "regex 1.0.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde 1.0.80 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde_json 1.0.32 (registry+https://github.com/rust-lang/crates.io-index)",
- "walkdir 2.2.5 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]

Cargo.toml

@@ -17,7 +17,7 @@ exclude = ["book-example/*"]
 [dependencies]
 clap = "2.24"
 chrono = "0.4"
-handlebars = "1.0"
+handlebars = { version = "1.0", default-features = false, features = ["no_dir_source"] }
 serde = "1.0"
 serde_derive = "1.0"
 error-chain = "0.12"