v0.3.0

New features

• Add new instance module with SetCover, CapacitatedFacilityLocation, IndependentSet, and CombinatorialAuction generator (implemented in Python).
• Add main source of randomness and ecole.seed(val) function for default random state (except in instance genertaors, upcoming) f3b68ca

Breaking changes

• Minimum C++ version moved to C++17 4d3d631
• Upgrade to Pybind 2.6 8879694