Document MSRV on README

.travis.yml

@@ -5,7 +5,7 @@ matrix:
     - env: TARGET=x86_64-unknown-linux-gnu
       if: (branch = staging OR branch = trying) OR (type = pull_request AND branch = master)
       # MSRV
-      rust: 1.31.0
+      rust: 1.32.0
 
 before_install:
   - set -e

README.md

@@ -11,6 +11,11 @@ This project is developed and maintained by the [Cortex-M team][team].
 
 ## [Documentation](https://docs.rs/crate/itm)
 
+## Minimum Supported Rust Version (MSRV)
+
+This crate is guaranteed to compile on stable Rust 1.32.0 and up. It *might*
+compile with older versions but that may change in any new patch release.
+
 ## License
 
 Licensed under either of