update to node 12.x

fixes missing globalThis in CI tests

.github/workflows/build-dev.yml

@@ -11,7 +11,7 @@ jobs:
     steps:
     - uses: actions/setup-node@v1
       with:
-        node-version: '10.x'
+        node-version: '12.x'
         registry-url: 'https://npm.pkg.github.com'
     - uses: actions/checkout@v2
     - run: yarn install

.github/workflows/test-pull-request.yml

@@ -15,7 +15,7 @@ jobs:
     steps:
     - uses: actions/setup-node@v1
       with:
-        node-version: '10.x'
+        node-version: '12.x'
         registry-url: 'https://npm.pkg.github.com'
     - uses: actions/checkout@v2
     - run: yarn install

.tool-versions

@@ -1 +1 @@
-nodejs 10.21.0
+nodejs 12.18.3

CONTRIBUTING.md

@@ -40,7 +40,7 @@ These are the required software tools you need to install on your computer.
 
 ### Node.js
 
-We are using [Node.js][node] v10.x. We recommend using a tool such as [asdf][asdf]
+We are using [Node.js][node] v12.x. We recommend using a tool such as [asdf][asdf]
 or [nvm][nvm] if you need to install more than one version of Node.js.
 
 [node]: https://nodejs.org/en/