newbie resources: update tour link to use https
newbie resources: update tour link to use https

The other links with working HTTPS support are already using the `https` scheme.
Let's do the same for the tour.

Signed-off-by: Tim Heckman <8efd86fb78a56a5145ed7739dcb00c78581c5375@heckman.io>

gopheracademy/gopher,gopheracademy/gopher