Replace Travis with Azure. (#498)

.editorconfig

@@ -3,7 +3,3 @@ root = true
 [*]
 indent_style = space
 indent_size = 4
-
-[.travis.yml]
-indent_style = space
-indent_size = 2

README.md

@@ -190,8 +190,8 @@ Building the `voice`-feature on Windows can be done by following these instructi
 [`rest`]: https://docs.rs/serenity/*/serenity/client/rest/index.html
 [`validate_token`]: https://docs.rs/serenity/*/serenity/client/fn.validate_token.html
 [cache docs]: https://docs.rs/serenity/*/serenity/cache/index.html
-[ci]: https://travis-ci.org/serenity-rs/serenity
-[ci-badge]: https://img.shields.io/travis/serenity-rs/serenity.svg?style=flat-square
+[ci]: https://dev.azure.com/serenity-org/serenity/_build?definitionId=1
+[ci-badge]: https://img.shields.io/azure-devops/build/serenity-org/1ce9579e-03bc-499f-9302-4180a2dfec6f/1/current.svg?style=flat-square
 [client's module-level documentation]: https://docs.rs/serenity/*/serenity/client/index.html
 [crates.io link]: https://crates.io/crates/serenity
 [crates.io version]: https://img.shields.io/crates/v/serenity.svg?style=flat-square