Update sliding.html.twig

in bootstrap v3. pagination class moved to <ul> element
Merge pull request #544 from birko/patch-1

Update sliding.html.twig
Use navbar-default as default for navbar-bs3

Bootstrap 3 has new class navbar-default for regular (white) navbar,
this should be used when not using inversed (black) navbar.
Merge pull request #545 from adriansm/master

Use navbar-default as default for navbar-bs3