RBAC installation gets requirements could not be resolved


I’m new to Yii2 framework and have been trying to install Yii2mod/yii2-rbac from GitHub repository (github.com/yii2mod/yii2-rbac). I have followed the mentioned steps but i’m getting the following error consistently and not able to install the RBAC.

Hostname:yii hamja$ php composer.phar require --prefer-dist yii2mod/yii2-rbac "*"

./composer.json has been updated

The "extra.asset-installer-paths" option is deprecated, use the "config.fxp-asset.installer-paths" option

Loading composer repositories with package information

Updating dependencies (including require-dev)

Your requirements could not be resolved to an installable set of packages.                               

  Problem 1

    - The requested package yii2mod/yii2-jui could not be found in any version, there may be a typo in the package name.

Potential causes:

 - A typo in the package name

 - The package is not available in a stable-enough version according to your minimum-stability setting

   see <Link to composer#minimum-stability> for more details.

Read <Link to composer troubleshooting> for further common problems.

Installation failed, reverting ./composer.json to its original content.

Hostname:yii hamja$

How do I resolve this issue? Is there any work around?

I’m running XAMPP on macOS Sierra.

Thank you in advance.

Mohamed Hamja