bump version number for tokio-boring

this is necessary so we can publish a version with the `fips` feature,
even though in practice the crate is exactly the same.

Author: jyn514

tokio-boring/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "tokio-boring"
-version = "2.1.4"
+version = "2.1.5"
 authors = ["Alex Crichton <alex@alexcrichton.com>", "Ivan Nikulin <ifaaan@gmail.com>"]
 license = "MIT/Apache-2.0"
 edition = "2018"