Update shell.nix

shell.nix

@@ -1,26 +1,13 @@
 with (import <nixpkgs> {});
 
-let
-  adafruit-ampy = python3Packages.buildPythonApplication rec {
-    pname = "adafruit-ampy";
-    version = "1.0.7";
-
-    src = python3Packages.fetchPypi {
-      inherit pname version;
-      sha256 = "1dz5sksalccv4c3bzk3c1jxpg3s28lwlw8hfwc9dfxhw3a1np3fd";
-    };
-
-    propagatedBuildInputs = with python3Packages; [ click python-dotenv setuptools_scm pyserial ];
-
-    # No tests
-    doCheck = false;
-  };
-
-in mkShell {
+mkShell {
   buildInputs = [
     adafruit-ampy
     esptool
     picocom
     gnumake
+
+    # For tests of new things
+    esphome
   ];
 }