chore: Update symbiotic version.

Bump version.

Removal of the obsolete script system-build.sh

transforms/ExplicitConsdes: Fix compilation with LLVM 12+

slowbeast: generate a trivial correctness witness

SV-COMP 2020 version

fix build scripts

Missing " in a previous commit.

fix generating testcases

SV-COMP 2019 version

The version used for SV-COMP 2019

witness: change from sha1 to sha256

Signed-off-by: Marek Chalupa <xchalup4@fi.muni.cz>