Add path_edit.py to bazel BUILD

Add the path_edit tool to bazel. Abstract out the shared base_window
class used for path_edit and graph_edit.

Change-Id: I8c3d493cfa7fc954e39da82210cf1cb7ec880b13
diff --git a/y2018/control_loops/python/BUILD b/y2018/control_loops/python/BUILD
index d445f8a..4e18423 100644
--- a/y2018/control_loops/python/BUILD
+++ b/y2018/control_loops/python/BUILD
@@ -160,18 +160,32 @@
     ],
 )
 
+py_library(
+    name = "basic_window",
+    srcs = [
+        "basic_window.py",
+    ],
+    restricted_to = ["//tools:k8"],
+    deps = [
+        ":python_init",
+        "@python_gtk",
+    ],
+)
+
 py_binary(
     name = "graph_edit",
     srcs = [
-        "basic_window.py",
         "graph_edit.py",
         "graph_generate.py",
     ],
     default_python_version = "PY3",
     legacy_create_init = False,
     srcs_version = "PY3",
+    restricted_to = ["//tools:k8"],
     deps = [
+        ":basic_window",
         ":python_init",
+        "@python_gtk",
     ],
 )
 
@@ -189,6 +203,22 @@
     ],
 )
 
+py_binary(
+    name = "path_edit",
+    srcs = [
+        "path_edit.py",
+    ],
+    default_python_version = "PY3",
+    legacy_create_init = False,
+    srcs_version = "PY3",
+    restricted_to = ["//tools:k8"],
+    deps = [
+        ":basic_window",
+        ":python_init",
+        "@python_gtk",
+    ],
+)
+
 py_library(
     name = "python_init",
     srcs = ["__init__.py"],
diff --git a/y2018/control_loops/python/path_edit.py b/y2018/control_loops/python/path_edit.py
index 885b36c..ce2118a 100644
--- a/y2018/control_loops/python/path_edit.py
+++ b/y2018/control_loops/python/path_edit.py
@@ -1,3 +1,5 @@
+#!/usr/bin/python3

+

 from __future__ import print_function

 import os

 import basic_window