Add zinken testnet (#1741)

## Issue Addressed

- Resolves #1722

## Proposed Changes

This extends @danielschonfeld's work in #1739 with:

- Use an empty boot node list
- Remove the genesis state

## Additional Info

NA


Co-authored-by: Daniel Schonfeld <daniel@schonfeld.org>

common/eth2_config/src/lib.rs

@@ -111,6 +111,8 @@ define_net!(medalla, include_medalla_file, "medalla", true);
 
 define_net!(spadina, include_spadina_file, "spadina", true);
 
+define_net!(zinken, include_zinken_file, "zinken", false);
+
 #[cfg(test)]
 mod tests {
     use super::*;

common/eth2_testnet_config/build.rs

@@ -1,6 +1,6 @@
 //! Downloads a testnet configuration from Github.
 
-use eth2_config::{altona, medalla, spadina, Eth2NetArchiveAndDirectory};
+use eth2_config::{altona, medalla, spadina, zinken, Eth2NetArchiveAndDirectory};
 use std::fs;
 use std::fs::File;
 use std::io;
@@ -10,6 +10,7 @@ const ETH2_NET_DIRS: &[Eth2NetArchiveAndDirectory<'static>] = &[
     altona::ETH2_NET_DIR,
     medalla::ETH2_NET_DIR,
     spadina::ETH2_NET_DIR,
+    zinken::ETH2_NET_DIR,
 ];
 
 fn main() {

common/eth2_testnet_config/src/lib.rs

@@ -7,7 +7,9 @@
 //!
 //! https://github.com/sigp/lighthouse/pull/605
 //!
-use eth2_config::{include_altona_file, include_medalla_file, include_spadina_file, unique_id};
+use eth2_config::{
+    include_altona_file, include_medalla_file, include_spadina_file, include_zinken_file, unique_id,
+};
 
 use enr::{CombinedKey, Enr};
 use ssz::{Decode, Encode};
@@ -54,8 +56,9 @@ macro_rules! define_net {
 const ALTONA: HardcodedNet = define_net!(altona, include_altona_file);
 const MEDALLA: HardcodedNet = define_net!(medalla, include_medalla_file);
 const SPADINA: HardcodedNet = define_net!(spadina, include_spadina_file);
+const ZINKEN: HardcodedNet = define_net!(zinken, include_zinken_file);
 
-const HARDCODED_NETS: &[HardcodedNet] = &[ALTONA, MEDALLA, SPADINA];
+const HARDCODED_NETS: &[HardcodedNet] = &[ALTONA, MEDALLA, SPADINA, ZINKEN];
 pub const DEFAULT_HARDCODED_TESTNET: &str = "medalla";
 
 /// Specifies an Eth2 testnet.

lighthouse/src/main.rs

@@ -114,7 +114,7 @@ fn main() {
                 .long("testnet")
                 .value_name("testnet")
                 .help("Name of network lighthouse will connect to")
-                .possible_values(&["medalla", "altona", "spadina"])
+                .possible_values(&["medalla", "altona", "spadina", "zinken"])
                 .conflicts_with("testnet-dir")
                 .takes_value(true)
                 .global(true)