gitignore doc/Doxyfile

Change-Id: Id4874adeac53d596419afa8b35c9aa384e5d68c3
Tuleap: #302
diff --git a/.gitignore b/.gitignore
index 567609b..61fec2a 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1 +1,2 @@
 build/
+doc/Doxyfile