Change tutorial examples to use v3 API

All the tutorial examples still use the v2 API. This patch converts them to v3
examples instead.

Signed-off-by: Ken Barber <ken@bob.sh>
Switch curl examples to v3 also

Signed-off-by: Ken Barber <ken@bob.sh>
Merge pull request #847 from kbarber/maint/1.5.x/switch-tutorial-to-use-v3-api

Change tutorial examples to use v3 API