.github/workflows: switch from Travis CI to GitHub Actions

So long, and thanks for all the builds!

.cirrus.yml

@@ -6,4 +6,4 @@ freebsd_12_task:
     image: freebsd-12-1-release-amd64
   install_script: pkg install -y go
   build_script: go build -v ./...
-  test_script: go test -v ./...
+  test_script: go test -race ./...

.github/workflows/interop.yml

@@ -1,7 +1,5 @@
 name: Interoperability tests
- 
 on: push
-
 jobs:
   trigger:
     runs-on: ubuntu-latest

.github/workflows/test.yml

@@ -0,0 +1,10 @@
+name: Go tests
+on: [push, pull_request]
+jobs:
+  test:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/setup-go@v2
+        with: { go-version: 1.x }
+      - uses: actions/checkout@v2
+      - run: go test -race ./...

.travis.yml

@@ -1,5 +0,0 @@
-os: linux
-arch: arm64
-dist: bionic
-language: go
-go: 1.x