Singular.jl 0.8.0 released

Today Singular.jl 0.8.0 has been released.

Diff since v0.7.0

Closed issues:

• Crash (#392)

Merged pull requests:

• Require Julia >= 1.6 (#501) (@fingolfin)
• [WIP] start non-commutative algebras (#503) (@tthsqe12)
• Type stable ideal (#504) (@tthsqe12)