simplify migrate script

.env

@@ -1,4 +1,4 @@
 RPC_NODE_URI=http://127.0.0.1:8545
 RESET_SNAPSHOT_ID=0x2
 NETWORK_ID=5777
-GAS_PRICE=1
+GAS_PRICE=1

migrations/2_deploy.js

@@ -1,27 +1,11 @@
-const DecimalMath = artifacts.require("DecimalMath");
-const SafeERC20 = artifacts.require("SafeERC20");
-const DODOMath = artifacts.require("DODOMath");
-const DODO = artifacts.require("DODO");
 const DODOZoo = artifacts.require("DODOZoo");
 
 module.exports = async (deployer, network) => {
-  const deployDODO = async () => {
-    await deployer.deploy(DecimalMath);
-    await deployer.deploy(SafeERC20);
-    await deployer.deploy(DODOMath);
-
-    await deployer.link(SafeERC20, DODO);
-    await deployer.link(DecimalMath, DODO);
-    await deployer.link(DODOMath, DODO);
-
-    await deployer.deploy(DODO);
+  const deployDODOZoo = async () => {
     await deployer.deploy(DODOZoo);
   };
 
-  if (network == "production") {
-  } else if (network == "kovan") {
-  } else {
-    // for development & test
-    await deployDODO();
+  if (network == "development") {
+    await deployDODOZoo();
   }
 };

package.json

@@ -47,6 +47,7 @@
     "web3-eth-contract": "^1.2.8"
   },
   "devDependencies": {
+    "@truffle/hdwallet-provider": "^1.0.36",
     "ganache-cli": "^6.9.1",
     "prettier": "^2.0.5",
     "prettier-plugin-solidity": "^1.0.0-alpha.52",