updated oldest supported rustc to 1.31.0.

Author: tov

.travis.yml

@@ -3,7 +3,7 @@ rust:
   - stable
   - beta
   - nightly
-  - 1.30.0
+  - 1.31.0
 
 dist: trusty
 sudo: false

CHANGELOG.md

@@ -8,6 +8,11 @@ The format is based on [Keep a Changelog] and this project adheres to
 [Keep a Changelog]: http://keepachangelog.com/en/1.0.0/
 [Semantic Versioning]: http://semver.org/spec/v2.0.0.html
 
+## [Unreleased]
+
+### Fixed
+- Oldest supported rustc version now documented to be 1.31.
+
 ## [0.7.0] - 2019-05-12
 
 ### Fixed

README.md

@@ -43,4 +43,4 @@ to your crate root.
 If you clone from github, be sure to `clone --recursive` to get the C
 libffi.
 
-This crate supports Rust version 1.30 and later.
+This crate supports Rust version 1.31 and later.

src/lib.rs

@@ -32,7 +32,7 @@
 //!
 //! to your crate root.
 //!
-//! This crate supports Rust version 1.30 and later.
+//! This crate supports Rust version 1.31 and later.
 
 #![allow(non_camel_case_types)]
 #![allow(non_snake_case)]