msrv: bump to Rust 1.41

This is in line with similar changes to the regex and memchr crates:
BurntSushi/memchr#82
and
rust-lang/regex#767

Author: BurntSushi

.github/workflows/ci.yml

@@ -31,7 +31,7 @@ jobs:
         include:
         - build: pinned
           os: ubuntu-18.04
-          rust: 1.28.0
+          rust: 1.41.1
         - build: stable
           os: ubuntu-18.04
           rust: stable

README.md

@@ -156,7 +156,7 @@ expression alternation. See `MatchKind` in the docs for more details.
 
 ### Minimum Rust version policy
 
-This crate's minimum supported `rustc` version is `1.28.0`.
+This crate's minimum supported `rustc` version is `1.41.1`.
 
 The current policy is that the minimum Rust version required to use this crate
 can be increased in minor version updates. For example, if `crate 1.0` requires