add flake

flake.lock

@@ -0,0 +1,27 @@
+{
+  "nodes": {
+    "nixpkgs": {
+      "locked": {
+        "lastModified": 1660646295,
+        "narHash": "sha256-V4G+egGRc3elXPTr7QLJ7r7yrYed0areIKDiIAlMLC8=",
+        "owner": "NixOS",
+        "repo": "nixpkgs",
+        "rev": "762b003329510ea855b4097a37511eb19c7077f0",
+        "type": "github"
+      },
+      "original": {
+        "owner": "NixOS",
+        "ref": "nixos-unstable",
+        "repo": "nixpkgs",
+        "type": "github"
+      }
+    },
+    "root": {
+      "inputs": {
+        "nixpkgs": "nixpkgs"
+      }
+    }
+  },
+  "root": "root",
+  "version": 7
+}

flake.nix

@@ -0,0 +1,19 @@
+{
+  description = "Description for the project";
+
+  inputs.nixpkgs.url = "github:NixOS/nixpkgs/nixos-unstable";
+
+  outputs = { self, nixpkgs, ... }: {
+    lib = import ./. {
+      inherit (nixpkgs) lib;
+    };
+    checks.x86_64-linux = let
+      pkgs = nixpkgs.legacyPackages.x86_64-linux;
+    in {
+      # Run tests: nix flake check -L
+      nixos-test = pkgs.callPackage ./tests/test.nix {
+        makeTest = import (pkgs.path + "/nixos/tests/make-test-python.nix");
+      };
+    };
+  };
+}