Add network sets and relax constraint on networks in fare_leg_join_rules.txt #578

[Skander Chouchene]

A pull request has been opened to relax the "same network join only" constraint in fare_leg_join_rules.txt to allow for multiple networks in effective fare legs and to add Network Sets to allow fare calculation for Effective Fare Legs with multiple networks.

Link: https://github.com/google/transit/pull/578