Interop chain start strategies (#479)

* Implement more flexible beacon chain genesis

* Fix compile issues from rebase on master

* Rename CLI flag

* Adds initial documentation for TOML files

* Update docs readme

* Add first version of cli_util

* Dont write cache fields in serde

* Tidy cli_util

* Add code to load genesis YAML file

* Move serde_utils out of tests in `types`

* Update logging text

* Fix serde YAML for Fork

* Make yaml hex decoding more strict

* Update deterministic key generate for interop

* Set deposit count on testing genesis state

* Make some fixes for deposit count

* Remove code fragements

* Large restructure of docs

* Tidy docs

* Fix readme link

* Add interop docs

* Tidy README

Cargo.toml

@@ -9,6 +9,7 @@ members = [
 	"eth2/utils/compare_fields",
 	"eth2/utils/compare_fields_derive",
 	"eth2/utils/eth2_config",
+	"eth2/utils/eth2_interop_keypairs",
 	"eth2/utils/hashing",
 	"eth2/utils/logging",
 	"eth2/utils/merkle_proof",
@@ -33,6 +34,7 @@ members = [
 	"beacon_node/version",
 	"beacon_node/beacon_chain",
 	"tests/ef_tests",
+	"tests/cli_util",
 	"protos",
 	"validator_client",
 	"account_manager",