Change --testnet flag to --network (#1751)

## Issue Addressed

- Resolves #1689

## Proposed Changes

TBC

## Additional Info

NA

common/eth2_testnet_config/src/lib.rs

@@ -14,7 +14,7 @@ use ssz::Decode;
 use std::fs::{create_dir_all, File};
 use std::io::{Read, Write};
 use std::path::PathBuf;
-use types::{Address, BeaconState, EthSpec, EthSpecId, YamlConfig};
+use types::{BeaconState, EthSpec, EthSpecId, YamlConfig};
 
 pub const ADDRESS_FILE: &str = "deposit_contract.txt";
 pub const DEPLOY_BLOCK_FILE: &str = "deploy_block.txt";
@@ -29,7 +29,6 @@ pub struct HardcodedNet {
     pub yaml_config: &'static [u8],
     pub deploy_block: &'static [u8],
     pub boot_enr: &'static [u8],
-    pub deposit_contract_address: &'static [u8],
     pub genesis_state_bytes: &'static [u8],
 }
 
@@ -43,7 +42,6 @@ macro_rules! define_net {
             yaml_config: $include_file!("../", "config.yaml"),
             deploy_block: $include_file!("../", "deploy_block.txt"),
             boot_enr: $include_file!("../", "boot_enr.yaml"),
-            deposit_contract_address: $include_file!("../", "deposit_contract.txt"),
             genesis_state_bytes: $include_file!("../", "genesis.ssz"),
         }
     }};
@@ -57,14 +55,13 @@ const MAINNET: HardcodedNet = define_net!(mainnet, include_mainnet_file);
 const TOLEDO: HardcodedNet = define_net!(toledo, include_toledo_file);
 
 const HARDCODED_NETS: &[HardcodedNet] = &[ALTONA, MEDALLA, SPADINA, PYRMONT, MAINNET, TOLEDO];
-pub const DEFAULT_HARDCODED_TESTNET: &str = "medalla";
+pub const DEFAULT_HARDCODED_TESTNET: &str = "mainnet";
 
 /// Specifies an Eth2 testnet.
 ///
 /// See the crate-level documentation for more details.
 #[derive(Clone, PartialEq, Debug)]
 pub struct Eth2TestnetConfig {
-    pub deposit_contract_address: String,
     /// Note: instead of the block where the contract is deployed, it is acceptable to set this
     /// value to be the block number where the first deposit occurs.
     pub deposit_contract_deploy_block: u64,
@@ -74,10 +71,6 @@ pub struct Eth2TestnetConfig {
 }
 
 impl Eth2TestnetConfig {
-    /// Returns the default hard coded testnet.
-    pub fn hard_coded_default() -> Result<Option<Self>, String> {
-        Self::constant(DEFAULT_HARDCODED_TESTNET)
-    }
     /// When Lighthouse is built it includes zero or more "hardcoded" network specifications. This
     /// function allows for instantiating one of these nets by name.
     pub fn constant(name: &str) -> Result<Option<Self>, String> {
@@ -91,8 +84,6 @@ impl Eth2TestnetConfig {
     /// Instantiates `Self` from a `HardcodedNet`.
     fn from_hardcoded_net(net: &HardcodedNet) -> Result<Self, String> {
         Ok(Self {
-            deposit_contract_address: serde_yaml::from_reader(net.deposit_contract_address)
-                .map_err(|e| format!("Unable to parse contract address: {:?}", e))?,
             deposit_contract_deploy_block: serde_yaml::from_reader(net.deploy_block)
                 .map_err(|e| format!("Unable to parse deploy block: {:?}", e))?,
             boot_enr: Some(
@@ -177,7 +168,6 @@ impl Eth2TestnetConfig {
             };
         }
 
-        write_to_yaml_file!(ADDRESS_FILE, self.deposit_contract_address);
         write_to_yaml_file!(DEPLOY_BLOCK_FILE, self.deposit_contract_deploy_block);
 
         if let Some(boot_enr) = &self.boot_enr {
@@ -225,7 +215,6 @@ impl Eth2TestnetConfig {
             };
         }
 
-        let deposit_contract_address = load_from_file!(ADDRESS_FILE);
         let deposit_contract_deploy_block = load_from_file!(DEPLOY_BLOCK_FILE);
         let boot_enr = optional_load_from_file!(BOOT_ENR_FILE);
         let yaml_config = optional_load_from_file!(YAML_CONFIG_FILE);
@@ -247,23 +236,12 @@ impl Eth2TestnetConfig {
         };
 
         Ok(Self {
-            deposit_contract_address,
             deposit_contract_deploy_block,
             boot_enr,
             genesis_state_bytes,
             yaml_config,
         })
     }
-
-    pub fn deposit_contract_address(&self) -> Result<Address, String> {
-        if self.deposit_contract_address.starts_with("0x") {
-            self.deposit_contract_address[2..]
-                .parse()
-                .map_err(|e| format!("Corrupted address, unable to parse: {:?}", e))
-        } else {
-            Err("Corrupted address, must start with 0x".to_string())
-        }
-    }
 }
 
 #[cfg(test)]
@@ -334,11 +312,9 @@ mod tests {
     ) {
         let temp_dir = TempDir::new("eth2_testnet_test").expect("should create temp dir");
         let base_dir = temp_dir.path().join("my_testnet");
-        let deposit_contract_address = "0xBB9bc244D798123fDe783fCc1C72d3Bb8C189413".to_string();
         let deposit_contract_deploy_block = 42;
 
         let testnet: Eth2TestnetConfig = Eth2TestnetConfig {
-            deposit_contract_address,
             deposit_contract_deploy_block,
             boot_enr,
             genesis_state_bytes: genesis_state.as_ref().map(Encode::as_ssz_bytes),