[pitivi] Add POTFILES.skip

[Piotr Drąg <piotrdrag src gnome org>]

commit cf53069547d76f2370b1bce87cf0f50f6b2d0957
Author: Piotr Drąg <piotrdrag gmail com>
Date:   Wed Jan 27 16:28:47 2016 +0100

    Add POTFILES.skip

 po/POTFILES.skip |    3 +++
 1 files changed, 3 insertions(+), 0 deletions(-)
---
diff --git a/po/POTFILES.skip b/po/POTFILES.skip
new file mode 100644
index 0000000..88b6148
--- /dev/null
+++ b/po/POTFILES.skip
@@ -0,0 +1,3 @@
+# List of source files that should *not* be translated.
+# Please keep this file sorted alphabetically.
+tests/test_media_library.py