nix: consolidate various shell.nix files into one

common/shell.nix

@@ -1,9 +0,0 @@
-with import <nixpkgs> {};
-
-let
-  myPython = python3.withPackages(p: [p.click p.graphviz p.trezor p.ed25519 p.pillow]) ;
-in
-  stdenv.mkDerivation {
-    name = "trezor-common-dev";
-    buildInputs = [ myPython python2Packages.demjson graphviz protobuf ];
-  }

core/shell.nix

@@ -1,9 +0,0 @@
-with import <nixpkgs> {};
-
-let
-  myPython = python3.withPackages(ps: [ps.trezor ps.pytest ps.flake8 ps.isort ps.black ps.Mako ps.munch ps.Pyro4 ps.pillow]);
-in
-  stdenv.mkDerivation {
-    name = "trezor-core-dev";
-    buildInputs = [ myPython protobuf scons gnumake gcc gcc-arm-embedded pkgconfig SDL2 SDL2_image autoflake clang-tools ];
-  }

crypto/shell.nix

@@ -1,6 +0,0 @@
-with import <nixpkgs> {};
-
-stdenv.mkDerivation {
-  name = "trezor-crypto-dev";
-  buildInputs = [ gnumake gcc pkgconfig openssl check valgrind clang-tools ];
-}

python/shell.nix

@@ -1,9 +0,0 @@
-with import <nixpkgs> {};
-
-let
-  myPython = python3.withPackages(p: [p.pytest p.black p.isort p.flake8 p.requests p.mnemonic p.construct p.pyblake2 p.mock p.ecdsa p.click p.libusb1 p.protobuf p.typing-extensions]);
-in
-  stdenv.mkDerivation {
-    name = "python-trezor-dev";
-    buildInputs = [ myPython autoflake protobuf ];
-  }

shell.nix

@@ -0,0 +1,39 @@
+with import <nixpkgs> {};
+
+let
+  MyPython = python3.withPackages(ps: [
+    ps.Mako
+    ps.Pyro4
+    ps.black
+    ps.ed25519
+    ps.flake8
+    ps.graphviz
+    ps.isort
+    ps.mock
+    ps.munch
+    ps.pillow
+    ps.pytest
+    ps.trezor
+  ]);
+in
+  stdenv.mkDerivation {
+    name = "trezor-firmware-dev";
+    buildInputs = [
+      MyPython
+      SDL2
+      SDL2_image
+      autoflake
+      check
+      clang-tools
+      gcc
+      gcc-arm-embedded
+      gnumake
+      graphviz
+      openssl
+      pkgconfig
+      protobuf
+      python2Packages.demjson
+      scons
+      valgrind
+    ];
+  }