enable github workflows

.github/workflows/build.yaml

@@ -0,0 +1,23 @@
+name: Build
+
+on:
+  push:
+    branches: [ master ]
+  pull_request:
+    branches: [ master ]
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/setup-go@v1
+      with:
+        go-version: 1.13
+      id: go
+
+    - uses: actions/checkout@v2
+
+    - run: go get -v -t -d ./...
+    - run: git submodule update --init --recursive --remote
+    - run: go test -v ./...
+

.github/workflows/goreleaser.yaml

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+name: goreleaser
+
+on:
+  push:
+    tags: ['*']
+
+jobs:
+  goreleaser:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v2
+      - run: git fetch --prune --unshallow
+      - uses: actions/setup-go@v1
+        with:
+          go-version: 1.13
+      - uses: goreleaser/goreleaser-action@v1
+        with:
+          args: release --rm-dist
+        env:
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}

.github/workflows/stale.yaml

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+name: Mark stale issues and pull requests
+
+on:
+  schedule:
+  - cron: "0 0 * * *"
+
+jobs:
+  stale:
+
+    runs-on: ubuntu-latest
+
+    steps:
+    - uses: actions/stale@v1
+      with:
+        repo-token: ${{ secrets.GITHUB_TOKEN }}
+        exempt-issue-label: 'exempt'
+        exempt-pr-label: 'exempt'