readme: fix badges

Fixes #797, Fixes #798

Author: BurntSushi

README.md

@@ -8,7 +8,7 @@ Much of the syntax and implementation is inspired
 by [RE2](https://github.com/google/re2).
 
 [![Build status](https://github.com/rust-lang/regex/workflows/ci/badge.svg)](https://github.com/rust-lang/regex/actions)
-[![](https://meritbadge.herokuapp.com/regex)](https://crates.io/crates/regex)
+[![Crates.io](https://img.shields.io/crates/v/regex.svg)](https://crates.io/crates/regex)
 [![Rust](https://img.shields.io/badge/rust-1.41.1%2B-blue.svg?maxAge=3600)](https://github.com/rust-lang/regex)
 
 ### Documentation

regex-syntax/README.md

@@ -2,9 +2,9 @@ regex-syntax
 ============
 This crate provides a robust regular expression parser.
 
-[![Build status](https://travis-ci.com/rust-lang/regex.svg?branch=master)](https://travis-ci.com/rust-lang/regex)
-[![Build status](https://ci.appveyor.com/api/projects/status/github/rust-lang/regex?svg=true)](https://ci.appveyor.com/project/rust-lang-libs/regex)
+[![Build status](https://github.com/rust-lang/regex/workflows/ci/badge.svg)](https://github.com/rust-lang/regex/actions)
 [![](https://meritbadge.herokuapp.com/regex-syntax)](https://crates.io/crates/regex-syntax)
+[![Crates.io](https://img.shields.io/crates/v/regex-syntax.svg)](https://crates.io/crates/regex-syntax)
 [![Rust](https://img.shields.io/badge/rust-1.28.0%2B-blue.svg?maxAge=3600)](https://github.com/rust-lang/regex)