Update to spec v1.0.0-rc.0 and BLSv4 (#1765)

## Issue Addressed

Closes #1504 
Closes #1505
Replaces #1703
Closes #1707

## Proposed Changes

* Update BLST and Milagro to versions compatible with BLSv4 spec
* Update Lighthouse to spec v1.0.0-rc.0, and update EF test vectors
* Use the v1.0.0 constants for `MainnetEthSpec`.
* Rename `InteropEthSpec` -> `V012LegacyEthSpec`
    * Change all constants to suit the mainnet `v0.12.3` specification (i.e., Medalla).
* Deprecate the `--spec` flag for the `lighthouse` binary
    * This value is now obtained from the `config_name` field of the `YamlConfig`.
        * Built in testnet YAML files have been updated.
    * Ignore the `--spec` value, if supplied, log a warning that it will be deprecated
    * `lcli` still has the spec flag, that's fine because it's dev tooling.
* Remove the `E: EthSpec` from `YamlConfig`
    * This means we need to deser the genesis `BeaconState` on-demand, but this is fine.
* Swap the old "minimal", "mainnet" strings over to the new `EthSpecId` enum.
* Always require a `CONFIG_NAME` field in `YamlConfig` (it used to have a default).

## Additional Info

Lots of breaking changes, do not merge! ~~We will likely need a Lighthouse v0.4.0 branch, and possibly a long-term v0.3.0 branch to keep Medalla alive~~.

Co-authored-by: Kirk Baird <baird.k@outlook.com>
Co-authored-by: Paul Hauner <paul@paulhauner.com>

lighthouse/environment/src/lib.rs

@@ -24,7 +24,7 @@ use std::path::PathBuf;
 use std::time::{SystemTime, UNIX_EPOCH};
 use task_executor::TaskExecutor;
 use tokio::runtime::{Builder as RuntimeBuilder, Runtime};
-use types::{EthSpec, InteropEthSpec, MainnetEthSpec, MinimalEthSpec};
+use types::{EthSpec, MainnetEthSpec, MinimalEthSpec, V012LegacyEthSpec};
 
 pub const ETH2_CONFIG_FILENAME: &str = "eth2-spec.toml";
 const LOG_CHANNEL_SIZE: usize = 2048;
@@ -37,7 +37,7 @@ pub struct EnvironmentBuilder<E: EthSpec> {
     log: Option<Logger>,
     eth_spec_instance: E,
     eth2_config: Eth2Config,
-    testnet: Option<Eth2TestnetConfig<E>>,
+    testnet: Option<Eth2TestnetConfig>,
 }
 
 impl EnvironmentBuilder<MinimalEthSpec> {
@@ -66,14 +66,14 @@ impl EnvironmentBuilder<MainnetEthSpec> {
     }
 }
 
-impl EnvironmentBuilder<InteropEthSpec> {
-    /// Creates a new builder using the `interop` eth2 specification.
-    pub fn interop() -> Self {
+impl EnvironmentBuilder<V012LegacyEthSpec> {
+    /// Creates a new builder using the v0.12.x eth2 specification.
+    pub fn v012_legacy() -> Self {
         Self {
             runtime: None,
             log: None,
-            eth_spec_instance: InteropEthSpec,
-            eth2_config: Eth2Config::interop(),
+            eth_spec_instance: V012LegacyEthSpec,
+            eth2_config: Eth2Config::v012_legacy(),
             testnet: None,
         }
     }
@@ -238,7 +238,7 @@ impl<E: EthSpec> EnvironmentBuilder<E> {
     /// Adds a testnet configuration to the environment.
     pub fn eth2_testnet_config(
         mut self,
-        eth2_testnet_config: Eth2TestnetConfig<E>,
+        eth2_testnet_config: Eth2TestnetConfig,
     ) -> Result<Self, String> {
         // Create a new chain spec from the default configuration.
         self.eth2_config.spec = eth2_testnet_config
@@ -249,7 +249,7 @@ impl<E: EthSpec> EnvironmentBuilder<E> {
             .ok_or_else(|| {
                 format!(
                     "The loaded config is not compatible with the {} spec",
-                    &self.eth2_config.spec_constants
+                    &self.eth2_config.eth_spec_id
                 )
             })?;
 
@@ -261,7 +261,7 @@ impl<E: EthSpec> EnvironmentBuilder<E> {
     /// Optionally adds a testnet configuration to the environment.
     pub fn optional_eth2_testnet_config(
         self,
-        optional_config: Option<Eth2TestnetConfig<E>>,
+        optional_config: Option<Eth2TestnetConfig>,
     ) -> Result<Self, String> {
         if let Some(config) = optional_config {
             self.eth2_testnet_config(config)
@@ -339,7 +339,7 @@ pub struct Environment<E: EthSpec> {
     log: Logger,
     eth_spec_instance: E,
     pub eth2_config: Eth2Config,
-    pub testnet: Option<Eth2TestnetConfig<E>>,
+    pub testnet: Option<Eth2TestnetConfig>,
 }
 
 impl<E: EthSpec> Environment<E> {

lighthouse/environment/tests/environment_builder.rs

@@ -3,17 +3,17 @@
 use environment::EnvironmentBuilder;
 use eth2_testnet_config::Eth2TestnetConfig;
 use std::path::PathBuf;
-use types::{MainnetEthSpec, YamlConfig};
+use types::{V012LegacyEthSpec, YamlConfig};
 
-fn builder() -> EnvironmentBuilder<MainnetEthSpec> {
-    EnvironmentBuilder::mainnet()
+fn builder() -> EnvironmentBuilder<V012LegacyEthSpec> {
+    EnvironmentBuilder::v012_legacy()
         .single_thread_tokio_runtime()
         .expect("should set runtime")
         .null_logger()
         .expect("should set logger")
 }
 
-fn eth2_testnet_config() -> Option<Eth2TestnetConfig<MainnetEthSpec>> {
+fn eth2_testnet_config() -> Option<Eth2TestnetConfig> {
     Eth2TestnetConfig::hard_coded_default().expect("should decode hard_coded params")
 }