EF spec tests clone problem

[protolambda]

All Client implementers have been helping us to reduce GitHub overhead, and download tests through the tarbal archives we provide. Cloning the spec-tests through git, even though it uses LFS, is very problematic for GitHub and CI providers, as it costs over a GB per clone, since it is not compressed during cloning. We merely use git for historical versioning, and it's not the intention to distribute it this way.

The tar files that are available however are much faster to download, and don't cause GitHub to rate-limit you when you clone more. Additionally, caching the spec-tests in your CI and local dev environment would be great.

May I suggest you add something like this to a makefile, to download the tests, and remove it as git submodule:

SPEC_VERSION ?= v0.11.1

clear-tests:
	rm -rf tests/spec/eth2.0-spec-tests

download-tests:
	mkdir -p tests/spec/eth2.0-spec-tests
	wget https://github.com/ethereum/eth2.0-spec-tests/releases/download/$(SPEC_VERSION)/general.tar.gz -O - | tar -xz -C tests/spec/eth2.0-spec-tests
	wget https://github.com/ethereum/eth2.0-spec-tests/releases/download/$(SPEC_VERSION)/minimal.tar.gz -O - | tar -xz -C tests/spec/eth2.0-spec-tests
	wget https://github.com/ethereum/eth2.0-spec-tests/releases/download/$(SPEC_VERSION)/mainnet.tar.gz -O - | tar -xz -C tests/spec/eth2.0-spec-tests

Thank you!

[ehildenb]

@protolambda can you make your changes as a PR instead? Then we can see if it works and fix it if it doesn't.