message: build: allow check-environment.js to be run directly
diff: @@ -53,6 +53,17 @@ try {
  printWarning(issues);
  }
  +if (require.main === module) {
  + // we are running this script directly so just run checkEnvironment against the main angular
  + // package.json
  + var engines = require(__dirname + '/../package.json').engines;
  + checkEnvironment({
  + requiredNodeVersion: engines.node,
  + requiredNpmVersion: engines.npm,
  + requiredYarnVersion: engines.yarn
  + });
  +}
  +
  function checkEnvironment(reqs) {
  exec('npm --version', function(npmErr, npmStdout) {
  exec('yarn --version', function(yarnErr, yarnStdout) {
  