ci: migrate to GH actions, upgrade Node to 10

Changes the build infrastructure to GH actions. As a prerequisite, Node was upgraded to 10.

BREAKING CHANGE: Minimal supported Node version is 10

Closes #76

.github/workflows/nodejs.yml

@@ -0,0 +1,24 @@
+name: Node.js CI
+
+on: [push]
+
+jobs:
+  build:
+
+    runs-on: ubuntu-latest
+
+    strategy:
+      matrix:
+        node-version: [10.x, 12.x]
+
+    steps:
+    - uses: actions/checkout@v2
+    - name: Use Node.js ${{ matrix.node-version }}
+      uses: actions/setup-node@v1
+      with:
+        node-version: ${{ matrix.node-version }}
+    - run: yarn install
+    - run: yarn run build
+    - run: yarn test:ci
+      env:
+        CI: true

.github/workflows/release.yml

@@ -0,0 +1,25 @@
+name: Release
+on:
+  push:
+    branches:
+      - master
+jobs:
+  release:
+    name: Release
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v1
+      - name: Setup Node.js
+        uses: actions/setup-node@v1
+        with:
+          node-version: 12
+      - name: Install dependencies
+        run: yarn install
+      - name: Build
+        run: yarn build
+      - name: Release
+        env:
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+          NPM_TOKEN: ${{ secrets.NPM_TOKEN }}
+        run: npx semantic-release

.nvmrc

@@ -0,0 +1 @@
+10