v0.8.0

QuadraticModels v0.8.0

Diff since v0.7.4

Merged pull requests:

• Add breakage tests (#83) (@tmigot)
• use push_preview = true in deploydocs (#84) (@dpo)
• Improve presolve (#85) (@geoffroyleconte)
• [PRESOLVE] Free linear singleton columns, row/col storage of A and H (#87) (@geoffroyleconte)
• Fix postsolve, check primal constraints (#90) (@geoffroyleconte)
• Define QMSolution type (#92) (@geoffroyleconte)
• Release 0.8.0 (#94) (@geoffroyleconte)