Navbar expand/collapse behavior

[mark-a-wilson]

At some screen resolutions, when the hamburger toggler is invoked, the nav menu expands horizontally across the navbar instead of below the navbar.

See screen demo:
https://drive.google.com/open?id=1ZvzlutGV7zGbuCiOSRzXJKTzNuafwjMB

Please fix this so that in all cases when the hamburger toggler is present, the nav menu expands/collapses underneath.

[mark-a-wilson]

PR has been submitted to fix this issue: #52

[mark-a-wilson]

PR merged into develop - 9c3cb7f. This should be resolved now.