old_contents: /* eslint-disable no-console, no-unused-expressions */
  var yargs = require('yargs')
    .command('migration', 'Show commands available for migrations')
    .example('$0 migration')
    .demand(1, 'Must provide a valid command');
  
  var argv = yargs.argv;
  var command = argv._[0];
  
  var commandModule = require('./' + command);
  
  if (typeof commandModule === 'function') {
    commandModule(yargs);
  } else {
    yargs.showHelp();
  }
  
new_contents: #!/usr/bin/env node
  /* eslint-disable no-console, no-unused-expressions */
  var yargs = require('yargs')
    .command('migration', 'Show commands available for migrations')
    .example('$0 migration')
    .demand(1, 'Must provide a valid command');
  
  var argv = yargs.argv;
  var command = argv._[0];
  
  var commandModule = require('./' + command);
  
  if (typeof commandModule === 'function') {
    commandModule(yargs);
  } else {
    yargs.showHelp();
  }
  
subject: set env on top of file.