Push Binary Cache for Nix

.github/workflows/nix-cache.yml

@@ -0,0 +1,18 @@
+name: "Push Binary Cache for Nix"
+on:
+  pull_request:
+  push:
+jobs:
+  tests:
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/checkout@v3
+    - uses: cachix/install-nix-action@v17
+      with:
+        nix_path: nixpkgs=channel:nixos-unstable
+    - uses: cachix/cachix-action@v11
+      with:
+        name: xplr
+        authToken: '${{ secrets.CACHIX_AUTH_TOKEN }}'
+    - run: nix-build
+    - run: nix-shell --run "xplr --version"