add scroll feature

[ayodkay]

nice if can add a scroll feature when there are more than 4 tabs,this can make the tab flexible for tab names with long character

[Droppers]

This might be possible by using another layout manager, since the tabs are already in a recyclerview.

I will have to look into this if it is possible without any major redesign, since this library is specifically designed to not allow scrolling.

I don't think it should scroll automatically, but through configuration option, e.g. abb_scrollable="true|false"