Update to remove_dir_all 0.6.0

Author: rbtcollins

Cargo.lock

@@ -40,7 +40,7 @@ openssl = {version = "0.10", optional = true}
 pulldown-cmark = {version = "0.7", default-features = false}
 rand = "0.7"
 regex = "1"
-remove_dir_all = "0.5.1"
+remove_dir_all = "0.6.0"
 same-file = "1"
 scopeguard = "1"
 semver = "0.9"