Add Windows CI with test run

.github/workflows/node.js.yml

@@ -0,0 +1,21 @@
+# This workflow will do a clean install of node dependencies, build the source code and run tests across different versions of node
+# For more information see: https://help.github.com/actions/language-and-framework-guides/using-nodejs-with-github-actions
+
+name: Node.js CI
+
+on:
+  push:
+    branches: [ main, ben/ci ]
+  pull_request:
+    branches: [ main, ben/ci ]
+
+jobs:
+  windows:
+    runs-on: ${{ matrix.os }}
+    strategy:
+      matrix:
+        os: [windows-latest]
+    steps:
+    - uses: actions/checkout@v2
+    - run: yarn install
+    - run: yarn test

.npmignore

@@ -1,3 +1,3 @@
 lib/test*
 .editorconfig
-appveyor.yml
+.github

README.md

@@ -1,6 +1,6 @@
 # windows-process-tree
 
-[![Build status](https://ci.appveyor.com/api/projects/status/ymp5m05kvcdtw6e7/branch/master?svg=true)](https://ci.appveyor.com/project/Tyriar/vscode-windows-process-tree/branch/master)
+[![Build status](https://github.com/microsoft/vscode-windows-process-tree/actions/workflows/node.js.yml/badge.svg)](https://github.com/microsoft/vscode-windows-process-tree/actions/workflows/node.js.yml)
 
 A Node.js library that enables quickly fetching process tree information for a particular process ID on Windows.