AWS CodeBuild adds Support for Polyglot Builds

[AWS CodeBuild](https://aws.amazon.com/codebuild/) now supports polyglot builds in [CodeBuild’s managed images](https://docs.aws.amazon.com/codebuild/latest/userguide/build-env-ref-available.html). Previously, you could only specify a single programming language runtime in these CodeBuild managed images. In order to perform a polyglot build, you either had to rely on a self-managed build images with various runtimes pre-installed or you had to install these additional runtimes inline in your buildspec. Now, you can simply [specify one or more programming language versions](https://docs.aws.amazon.com/codebuild/latest/userguide/sample-runtime-versions.html#sample-runtime-two-major-version-runtimes) in your buildspec for your build needs. This is made possible by a concept called "runtime-versions". With runtime-versions, you can also [specify which major version](https://docs.aws.amazon.com/codebuild/latest/userguide/sample-runtime-versions.html#sample-runtime-update-version) of the runtime should be enabled for your builds. To learn more about "runtime-versions" please visit our [documentation](https://docs.aws.amazon.com/codebuild/latest/userguide/sample-runtime-versions.html). Please visit our [product page](https://aws.amazon.com/codebuild/) or [the console](https://console.aws.amazon.com/codebuild) to learn more about how to get started with AWS CodeBuild.