add spinner when fetching the proposal

Author: aduh95

lib/promote_release.js

@@ -69,9 +69,11 @@ export default class ReleasePromotion extends Session {
     }
     if (!localCloneIsClean) {
       if (await cli.prompt('Should we reset the local HEAD to be the release proposal?')) {
+        cli.startSpinner('Fetching the proposal upstream...');
         await forceRunAsync('git', ['fetch', this.upstream, releaseCommitSha],
           { ignoreFailure: false });
         await forceRunAsync('git', ['reset', releaseCommitSha, '--hard'], { ignoreFailure: false });
+        cli.stopSpinner('Local HEAD is now in sync with the proposal');
       } else {
         cli.error('Local clone is not ready');
         throw new Error('Aborted');