ci: replace CircleCI with GitHub Actions

.github/workflows/ci.yml

@@ -0,0 +1,26 @@
+name: continuous-integration
+on: [push, pull_request]
+jobs:
+  build:
+    strategy:
+      fail-fast: false
+      matrix:
+        os: [ubuntu-latest, windows-latest, macos-latest]
+    runs-on: ${{ matrix.os }}
+
+    steps:
+      - name: Set up Go 1.13
+        uses: actions/setup-go@v1
+        with:
+          go-version: 1.13
+
+      - name: Check out code into the Go module directory
+        uses: actions/checkout@v2
+
+      - name: Verify dependencies
+        run: go mod verify
+
+      - name: Build
+        shell: bash
+        run: |
+          go build -v ./cmd/tog

.github/workflows/release.yml

@@ -0,0 +1,24 @@
+name: goreleaser
+
+on:
+  push:
+    tags:
+      - "v*"
+
+jobs:
+  goreleaser:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v2
+      - name: Set up Go 1.13
+        uses: actions/setup-go@v1
+        with:
+          go-version: 1.13
+      - name: Run GoReleaser
+        uses: goreleaser/goreleaser-action@v1
+        with:
+          version: latest
+          args: release
+        env:
+          GITHUB_TOKEN: ${{secrets.RELEASE_GITHUB_TOKEN}}