message: Send a 400 failure response when the contribution URL is not under github domain which we are not supporting yet.
diff: @@ -36,22 +36,21 @@ export class ContribInstallController {
  * @returns results.fail {array} array of installation failed contribution urls
  */
  install(url) {
  - let results;
  return this.installContributions(url)
  .then(installResults => {
  - results = installResults;
  - if (results.fail.length === 0) {
  + if (installResults.fail.length === 0) {
  return this.buildEngine()
  .then(() => {
  logger.debug(`Restarting the engine upon successful '${url}' installation.`);
  return this.restartEngineAfterBuild();
  })
  - .then(() => this.updateContribsDB());
  + .then(() => this.updateContribsDB())
  + .then(() => this.removeBackup())
  + .then(() => installResults);
  } else {
  - return results;
  + throw new Error('Cannot install a contribution outside github domain');
  }
  - }).then(() => this.removeBackup())
  - .then(() => results)
  + })
  .catch(err => {
  logger.error(`[error] Encountered error while installing the '${url}' to the engine: `);
  logger.error(err);
  