Trying to install packages in Larave 5

I was trying to install the package of HOA/Websockets in my Laravel5 website ,

from following link

http://ift.tt/1OId7ki

But when I added the

"require": {
        "hoa/websocket": "~2.0"
    }

In my composer and ran

composer install 

But in my command promt it says nothing to be installed Can any one help me out with this ,

Please Also when I try to do

composer require "hoa/websocket": "~2.0"

it is uninstalling some of the packages and not installing it back

Thanks in advance

via Chebli Mohamed