message: fix(build): use `latest` as default engine version
  To fix build
diff: @@ -30,8 +30,8 @@ const defaultEngineName = 'flogo-web';
  const defaultEngine = path.join(enginesRoot, defaultEngineName);
  let libVersion = process.env.FLOGO_LIB_VERSION || process.env.FLOGO_WEB_LIB_VERSION;
  -if (!libVersion || libVersion === 'latest') {
  - libVersion = 'master';
  +if (!libVersion) {
  + libVersion = 'latest';
  }
  const config = {
  