Add SANDAG 1 and 2 Zone examples

[esanchez01]

Addresses: #431

Adds the SANDAG 1 and 2 Zone examples. Additionally, updates the SANDAG 3 zone example structure and data.

[bstabler]

thanks @esanchez01. can you issue a PR to https://github.com/ActivitySim/activitysim_resources as well when you get a chance?

[coveralls]

Coverage decreased (-0.03%) to 56.312% when pulling 27649b7 on esanchez01:develop into 85f48ac on ActivitySim:develop.

[coveralls]

Coverage decreased (-0.03%) to 56.312% when pulling 23bba94 on esanchez01:develop into 85f48ac on ActivitySim:develop.

[bstabler]

this is blocked by #457 and #458. Once we pull those, we'll process this PR.

[bstabler]

@esanchez01 - let's make sure to update the 1, 2, and 3 zone system setups. Thanks!

[bstabler]

on the 8/17 call @esanchez01 said he's still working on getting this ready. Once pulled, @jpn-- will complete #439

[esanchez01]

@bstabler, this is now ready. PR has been issued to https://github.com/ActivitySim/activitysim_resources as well.

[bstabler]

#475