Replace circleci with github actions

.github/workflows/golangci-lint.yaml

@@ -0,0 +1,19 @@
+name: golangci-lint
+on:
+  push:
+    tags:
+      - v*
+    branches:
+      - master
+      - main
+      - v2
+  pull_request:
+
+jobs:
+  golangci:
+    name: lint
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v2
+      - name: golangci-lint
+        uses: golangci/golangci-lint-action@v2

.github/workflows/test.yaml

@@ -0,0 +1,25 @@
+on: [push, pull_request]
+name: Test
+jobs:
+  test:
+    strategy:
+      matrix:
+        go-version: [1.15.x, 1.16.x, 1.17.x]
+        os: [ubuntu-latest]
+    runs-on: ${{ matrix.os }}
+
+    steps:
+      - name:   Install Linux packages
+        if:     matrix.os == 'ubuntu-latest'
+        run:    sudo apt update && sudo apt install -y --no-install-recommends ffmpeg
+
+      - name:   Install Go
+        uses:   actions/setup-go@v2
+        with:
+          go-version: ${{ matrix.go-version }}
+
+      - name:   Checkout code
+        uses:   actions/checkout@v2
+
+      - name:   Test
+        run:    go test -v ./...