Move mock request_airdrop_transaction into drone/, closer to the real impl

drone/src/drone_mock.rs

@@ -0,0 +1,23 @@
+use solana_sdk::hash::Hash;
+use solana_sdk::pubkey::Pubkey;
+use solana_sdk::signature::{Keypair, KeypairUtil};
+use solana_sdk::system_transaction::SystemTransaction;
+use solana_sdk::transaction::Transaction;
+use std::io::{Error, ErrorKind};
+use std::net::SocketAddr;
+
+pub fn request_airdrop_transaction(
+    _drone_addr: &SocketAddr,
+    _id: &Pubkey,
+    lamports: u64,
+    _blockhash: Hash,
+) -> Result<Transaction, Error> {
+    if lamports == 0 {
+        Err(Error::new(ErrorKind::Other, "Airdrop failed"))?
+    }
+    let key = Keypair::new();
+    let to = Keypair::new().pubkey();
+    let blockhash = Hash::default();
+    let tx = SystemTransaction::new_account(&key, &to, lamports, blockhash, 0);
+    Ok(tx)
+}

drone/src/lib.rs

@@ -1 +1,2 @@
 pub mod drone;
+pub mod drone_mock;