message: Use require only locally
diff: /* eslint-env node */
  -const local = require('./local');
  -
  const knownBackends = {
  local: {
  url: 'http://localhost:5000/',
  @@ -196,7 +194,7 @@ module.exports = function(environment) {
  const BACKEND = process.env.BACKEND || 'local';
  // if no local.js, env vars need to be passed
  - const configFileSettings = BACKEND === 'local' ? local : {};
  + const configFileSettings = BACKEND === 'local' && environment === 'local' ? require('./local') : {}; // eslint-disable-line global-require
  const eitherConfig = envOrSource(process.env, configFileSettings);
  