Use a layout

* Create a application.html.erb in app/views/layouts
* Copy the common (surrounding) HTML into it
* Remove the common (surrounding) HTML from the templates
* Use the default layout in controllers
Change the layout to display links and title

* Use instance variables in the templates to set current_page and title
* Use the same instance variables in layout to display correctly the links and title
Use data from controller to display members list

* Make a protected method in the controller to get the members data
* Pass the members data through an instance variable
* Use the instance variable in the view to render the content
Merge pull request #28 from xarisd/05-layout

05 layout
Merge pull request #29 from xarisd/06-use-controller-instance-variable

Use data from controller to display members list