Strip out old code

All of these files have been moved to either:

- https://github.com/sigp/lighthouse-beacon
- https://github.com/sigp/lighthouse-validator
- https://github.com/sigp/lighthouse-common

For rationale, see: https://github.com/sigp/lighthouse/issues/197

eth2/block_producer/Cargo.toml

@@ -1,10 +0,0 @@
-[package]
-name = "block_producer"
-version = "0.1.0"
-authors = ["Paul Hauner <paul@paulhauner.com>"]
-edition = "2018"
-
-[dependencies]
-slot_clock = { path = "../../eth2/utils/slot_clock" }
-ssz = { path = "../../eth2/utils/ssz" }
-types = { path = "../../eth2/types" }