message: Ensure lib/ exists when generating json-schema
diff: @@ -114,6 +114,9 @@ task('json-schema', function () {
  const inPath = 'src/analysis-format/analysis-format.ts';
  const outPath = 'lib/analysis.schema.json';
  const command = path.normalize(`node_modules/.bin/typescript-json-schema`);
  + try {
  + fs.mkdirSync('lib');
  + } catch(e) { /* probably already exists, don't care */ }
  const child = child_process.spawn(
  command,
  [`--required`, `--ignoreErrors`, `${inPath}`, `Analysis`],
  