Pyscipopt

Added
Fixed
- close file descriptors after file operation is finished
- fixed deletion of variable pointer from model when calling delVar
- fixed scip install for MAC integration test
- Fixing assert failure if scip is compiled using quadprecision
- fixed missing GIL by AntoinePrv in 539
Changed
- changed integration test to include scip TPI (tinycthreads)
Removed
- removed Mac integration test until the segmentation fault in test_memory.py is fixed on Mac

Added
- add support for concurrent optimization
- note that SCIP needs to be linked to a TPI (task processing interface) to use this feature
- SCIPsolverConcurrent implementation from issue 229 by TNonet in 535
- fix action to also run on external PRs by mattmilten in 536
- fix concurrent solve test by mattmilten in 537

Added
- add SCIP function `getPseudoBranchCands`

Fixed
Changed
Removed

Added
- add SCIP functions `getNSolsFound`, `getNSolsFound`, `getNLimSolsFound` and `getNBestSolsFound`

Fixed
Changed
- documentation build parameter EXTRACT_ALL = YES

Removed

Added
- Continuous Integration: move from travis to github actions:
- integration with scipoptsuite and
- publishing documentation and packages.

Fixed
Changed
Removed
- CI files

Added
- add convenience function `Model.addConss()` to add multiple constraints at once