function getOutput(runningProcess) {
	let stdout = "";
	let stderr = "";

	runningProcess.stdout.on("data", data => (stdout += data));
	runningProcess.stderr.on("data", data => (stderr += data));
	return awaitExit(runningProcess).then(() => ({ stdout, stderr }));
}
Returns a Promise for the stdout of a process.
@param {ChildProcess} runningProcess The child process
@returns {Promise<{stdout: string, stderr: string}>} A Promise that fulfills with all of the
stdout and stderr output produced by the process when it exits.