add multi-stage taxi trip to SaoPauloTaxiPredictor

[MayuriAnn]

As suggested in #191 (comment), I followed the code on

eqasim-java/core/src/main/java/org/eqasim/core/simulation/mode_choice/utilities/predictors/CarPredictor.java

Lines 36 to 45 in a8a73b5

	for (Leg leg : TripStructureUtils.getLegs(elements)) {
	if (leg.getMode().equals(TransportMode.car)) {
	Verify.verify(!foundCar);
	carTravelTime_min += leg.getTravelTime().seconds() / 60.0;
	} else if (leg.getMode().equals(TransportMode.walk)) {
	accessEgressTime_min += leg.getTravelTime().seconds() / 60.0;
	} else {
	throw new IllegalStateException("Unexpected mode in car chain: " + leg.getMode());
	}
	}

to update the code of SaoPauloTaxiPredictor class.

[balacmi]

Thank you for looking into this. Can you please address my above comments and I will merge the PR.

[MayuriAnn]

Please check if its correct now.

[balacmi]

Looks good, thank you.

[balacmi]

May I also ask you to add to the CHANGELOG.md file the update you made, so we can keep track of what changed between releases.

[MayuriAnn]

May I also ask you to add to the CHANGELOG.md file the update you made, so we can keep track of what changed between releases.

Done.

[balacmi]

Great