nodrop: Add feature flag use_needs_drop; Tag version 0.1.5

nodrop/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "nodrop"
-version = "0.1.4"
+version = "0.1.5"
 authors = ["bluss"]
 
 license = "MIT/Apache-2.0"
@@ -17,5 +17,9 @@ keywords = ["container", "drop"]
 # Use no drop flag. See API doc for more info.
 no_drop_flag = []
 
+# Optional, nightly channel
+# Use `needs_drop` to skip overwriting if not necessary
+use_needs_drop = []
+
 [dependencies.odds]
 version = "0.2"