Updates for v0.9.2 of beacon chain spec

[ralexstokes]

What is wrong?

https://github.com/ethereum/eth2.0-specs/releases/tag/v0.9.2

How can it be fixed

Some of this is building on PRs we currently have open.

Concrete things to solve:

• update spec fixtures to v0.9.2
• fork choice updates in Forkchoice mods consensus-specs#1477
• reduce validator count, cf. reduce genesis validator count for mainnet config consensus-specs#1467

[ralexstokes]

I think it makes sense for me to continue the fork choice updates here after I finish the lingering stuff from v0.9.1

[ralexstokes]

@hwwhww anything we need to do on our side for ethereum/consensus-specs#1484 or ethereum/consensus-specs#1476 ?

[ralexstokes]

pending any updates to the string of PRs addressing the items in this issue and any stuff to resolve from this comment #1321 (comment), we can go ahead and close this issue

[ralexstokes]

this issue has been resolved :)