update changelog

Author: softprops

CHANGELOG.md

@@ -1,6 +1,7 @@
 #  0.2.0-rust-1.32.0 (unreleased)
 
 * Upgrade to Rust [`1.32.0`](https://blog.rust-lang.org/2019/01/17/Rust-1.32.0.html)
+* Add support to provide an explicit binary to package though `BIN` env variable
 
 # 0.2.0-rust-1.31.1