fix node version

.github/workflows/ci.yml

@@ -1,11 +1,6 @@
 name: CI
 on: [push]
 
-env:
-  MAINNET_URL: ${{ secrets.MAINNET_URL }}
-  MAINNET_PK: ${{ secrets.MAINNET_PK }}
-  ETHERSCAN_API_KEY: ${{ secrets.ETHERSCAN_API_KEY }}
-
 jobs:
   test:
     name: hardhat tests
@@ -18,7 +13,7 @@ jobs:
         uses: actions/setup-node@v3
         with:
           cache: yarn
-          node-version: 16
+          node-version: 18
 
       - name: install node deps
         run: yarn install --frozen-lockfile

package.json

@@ -11,6 +11,10 @@
     "test": "yarn hardhat test",
     "prepack": "yarn clean && yarn check:format && yarn test && yarn build"
   },
+  "engines": {
+    "node": ">=18.0.0 <19"
+  },
+  "packageManager": "[email protected]",
   "files": ["contracts/**/*.sol"],
   "keywords": ["solidity", "stateless", "shuffle", "feistel", "cipher", "fpe"],
   "author": "Kevin Charm <[email protected]>",