message: Fixed code coverage and appveyor badges.
diff: <img src="https://travis-ci.org/japaric/criterion.rs.svg?branch=master" alt="Travis-CI">
  </a>
  |
  - <a href="https://ci.appveyor.com/project/bheisler/criterion-rs-vt9fl">
  + <a href="https://ci.appveyor.com/project/japaric/criterion-rs-vt9fl">
  <img src="https://ci.appveyor.com/api/projects/status/4255ads9ctpupcl2?svg=true" alt="Appveyor">
  </a>
  |
  <img src="https://img.shields.io/crates/v/criterion.svg" alt="Crates.io">
  </a>
  |
  - <a href="https://coveralls.io/github/bheisler/criterion.rs?branch=master">
  - <img src="https://coveralls.io/repos/github/bheisler/criterion.rs/badge.svg?branch=master" alt="Coverage Status">
  + <a href="https://coveralls.io/github/japaric/criterion.rs?branch=master">
  + <img src="https://coveralls.io/repos/github/japaric/criterion.rs/badge.svg?branch=master" alt="Coverage Status">
  </a>
  </div>
  