ci: migrate from travis to github actions

.github/workflows/release-preview.yml

@@ -0,0 +1,13 @@
+name: Release preview
+on: [pull_request]
+jobs:
+  release-preview:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v3
+      - uses: actions/setup-node@v3
+        with:
+          node-version: 18
+      # semantic-release dry-run workaround https://github.com/semantic-release/semantic-release/issues/1890#issuecomment-974512960
+      - run: git checkout -b ${{ github.head_ref }}
+      - run: unset GITHUB_ACTIONS && yarn && node ./bin/semantic-release-github-pr --debug --branches ${{ github.head_ref }}

.github/workflows/release.yml

@@ -0,0 +1,22 @@
+name: Release
+
+on:
+  pull_request:
+    branches:
+      - master
+    types:
+      - closed
+
+jobs:
+  release:
+    if: github.event.pull_request.merged == true
+    runs-on: ubuntu-latest
+    env:
+      GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+      NPM_TOKEN: ${{ secrets.NPM_TOKEN }}
+    steps:
+      - uses: actions/checkout@v3
+      - uses: actions/setup-node@v3
+        with:
+          node-version: 18  
+      - run: npx semantic-release --debug

.github/workflows/tests.yml

@@ -0,0 +1,11 @@
+name: Tests
+on: [pull_request]
+jobs:
+  run-tests:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v3
+      - uses: actions/setup-node@v3
+        with:
+          node-version: 18
+      - run: yarn && yarn test

bin/semantic-release-github-pr.js

@@ -1,16 +1,12 @@
 #!/usr/bin/env node
 const execa = require('execa');
-const envCi = require('env-ci');
 const { argv } = process;
 const { resolve } = require('path');
 const { getCurrentBranchName } = require('../src/git-utils');
 
 (async function() {
   const plugins = `${resolve(__dirname, '../src/index.js')}`;
-  const currentBranchName = await getCurrentBranchName();
-  // If we're in a "detached HEAD" state, assume we're running on CI.
-  const branch =
-    currentBranchName !== 'HEAD' ? currentBranchName : envCi().prBranch;
+  const branch =  await getCurrentBranchName();
 
   const args = argv.slice(2).concat([
     // We want to run on pull request builds, but `semantic-release` won't