Migrate to GitHub Actions from CircleCI

.github/workflows/ci.yml

@@ -0,0 +1,29 @@
+---
+name: CI
+
+on: [push, pull_request]
+
+jobs:
+  vanilla:
+    runs-on: ubuntu-20.04
+    steps:
+      - uses: actions/checkout@v3
+      - run: sudo apt-get update && sudo apt-get install -y make build-essential
+      - run: make vanilla
+  reproducibility:
+    runs-on: ubuntu-20.04
+    steps:
+      # - run: sudo systemctl status docker
+      # - run: docker ps -a
+      - uses: actions/checkout@v3
+      - run: echo $PWD
+      - run: kernel_dir="$PWD/build" && mkdir -p -m 755 "$kernel_dir"
+      # - run: sudo apt-get update && sudo apt-get install -y make build-essential reprotest
+      # - run: make reprotest
+      # - run: ./scripts/build-kernel-wrapper
+  # reproducibility-securedrop:
+  #   runs-on: ubuntu-20.04
+  #   steps:
+  #     - uses: actions/checkout@v3
+  #     - run: sudo apt-get update && sudo apt-get install -y make build-essential reprotest
+  #     - run: make reprotest-sd