Rename "dir" variables

The variable name "dir" conflicts with the name of a Python built-in
function: http://docs.python.org/library/functions.html#dir

Change-Id: I850f3ec8df7563dc85e21f2876fe5e6550ca2d8f
diff --git a/project.py b/project.py
index d81152c..96ab907 100644
--- a/project.py
+++ b/project.py
@@ -209,9 +209,9 @@
         if os.path.exists(dest):
           os.remove(dest)
         else:
-          dir = os.path.dirname(dest)
-          if not os.path.isdir(dir):
-            os.makedirs(dir)
+          dest_dir = os.path.dirname(dest)
+          if not os.path.isdir(dest_dir):
+            os.makedirs(dest_dir)
         shutil.copy(src, dest)
         # make the file read-only
         mode = os.stat(dest)[stat.ST_MODE]