cross-ci/lib/var/BUILD_VERSION.d.ts

`cross-ci` standardizes environment variables for CI. For example, your can simply use `BUILD_BRANCH` variable in all CI runners instead of `CIRCLE_BRANCH` in CircleCI or `TRAVIS_PULL_REQUEST_BRANCH` in Travis.

import { ICrossCIVars } from '../createVars';
declare const BUILD_VERSION: ({ IS_PR, PROJECT_VERSION, BUILD_BRANCH, BUILD_PR_NUM, BUILD_NUM }: ICrossCIVars) => string;
export = BUILD_VERSION;