Update Committee Helpers

[terencechain]

Part of #2307

This PR is temporally blocked by #2350. To wrap up compute_committee I'll need get_permuted_index

What changes in this PR:

• Update get_epoch_committee_count
• Update get_shard_delta
• Update compute_committee
• Update get_crosslink_committees_at_slot

[codecov]

Codecov Report

Merging #2354 into spec-v0.6 will decrease coverage by 0.01%.
The diff coverage is 100%.

@@              Coverage Diff              @@
##           spec-v0.6    #2354      +/-   ##
=============================================
- Coverage      68.36%   68.35%   -0.02%     
=============================================
  Files            117      117              
  Lines           9234     9236       +2     
=============================================
  Hits            6313     6313              
- Misses          2244     2245       +1     
- Partials         677      678       +1

[shayzluf]

@terencechain I am working on permutatedIndex needed for compute_committee working on making the shuffle yaml to work. will push it when it parse and we will test it when you are done?

added t.Skip() with TODO to TestFromYaml_Pass
after completing compute committee

[terencechain]

@terencechain I am working on permutatedIndex needed for compute_committee working on making the shuffle yaml to work. will push it when it parse and we will test it when you are done?

added t.Skip() with TODO to TestFromYaml_Pass
after completing compute committee

Not sure if I follow, Im working on compute_committee in this PR which needs permutatedIndex. #2350 is blocking this PR right now. You can skip TestFromYaml_Pass but add a todo there.

[terencechain]

Thanks @0xKiwi !