message: utils: add `exec` and `print` convenience functions
diff: 'use strict';
  +import {execFileSync} from 'child_process';
  import {
  createReadStream,
  createWriteStream,
  @@ -18,3 +19,11 @@ import {
  export function cp(source: string, destination: string): void {
  createReadStream(source).pipe(createWriteStream(destination));
  }
  +
  +export function exec(executable: string, ...args: string[]): void {
  + print(execFileSync(executable, args).toString());
  +}
  +
  +export function print(string: string): void {
  + process.stdout.write(string);
  +}
  