Update for v7

[zhenbinwu]

It is still not clear whether we want to do a partial update or rerun. This will come from @scarletnorberg's study.

But we should keep track of what changes are expected using this issue.

• fullsim btag light/heavy systematic
• 2018 btag SF update

[scarletnorberg]

The Fullsim btag light/heavy the code is already updated this is why we do not need to rerun fastsim which includes both fastsim weights and fullsim weights.