Release 1.7.0

Merged in the LRAT support by Florian Pollitt (@florianpollitt) as described in our SAT'23 tool paper.

Florian Pollitt, Mathias Fleury and Armin Biere. Faster LRAT Checking than Solving with CaDiCaL.
In Proceedings 26th International Conference on Theory and Applications of Satisfiability Testing,
July 4-8, Alghero, Italy, published by LIPIcs, 2023.