Document MSRV 1.23.0

Author: eldruin

.travis.yml

@@ -1,7 +1,8 @@
 sudo: false
 language: rust
+# MSRV
 rust:
-  - 1.23.0 # oldest supported version
+  - 1.23.0
   - stable
   - beta
   - nightly

README.md

@@ -58,6 +58,12 @@ fn main() {
 }
 ```
 
+Minimum Supported Rust Version (MSRV)
+-------------------------------------
+
+This crate is guaranteed to compile on stable Rust 1.23.0 and up. It *might*
+compile with older versions but that may change in any new patch release.
+
 License
 -------