chore: update nodejs version (#74)

* chore: update nodejs version

* ci: remove node v12 from build-test matrix

.github/workflows/build-test.yml

@@ -11,7 +11,7 @@ jobs:
     runs-on: ubuntu-20.04
     strategy:
       matrix:
-        node-version: [12.x, 14.x, 16.x]
+        node-version: [14.x, 16.x]
     steps:
       - uses: actions/checkout@v2
       - name: Use Node.js ${{ matrix.node-version }}

.nvmrc

@@ -1 +1 @@
-v12
+v14

package.json

@@ -4,7 +4,7 @@
   "description": "[json-rpc-engine](https://github.com/MetaMask/json-rpc-engine) middleware implementing ethereum filter methods. Backed by an [eth-block-tracker](https://github.com/MetaMask/eth-block-tracker) and web3 provider interface (`web3.currentProvider`).",
   "main": "index.js",
   "engines": {
-    "node": ">=12.0.0"
+    "node": ">=14.0.0"
   },
   "scripts": {
     "build": "echo 'this does nothing'",