Setting credentials for https git clone in AWS CodeBuild

CodeBuild now provides an easier dial for this buildspec by setting the "git-credential-helper" to yes. Documentation @ https://docs.aws.amazon.com/codebuild/latest/userguide/build-spec-ref.html#build-spec-ref-syntax

Since the CodeBuild environment uses an IAM role for credentials (not a username and password), you will need to configure the CodeCommit credential helper in your buildspec:

phases:
  install:
    commands:
      - git config --global credential.helper '!aws codecommit credential-helper $@'
      - git config --global credential.UseHttpPath true