[gobject-introspection] Add missing maintainer tools to EXTRA_DIST

[Dieter Verfaillie <dieterv src gnome org>]

commit 7acb99addfca10427c4ace086fec6e3cff08c141
Author: Dieter Verfaillie <dieterv optionexplicit be>
Date:   Mon Jun 29 17:20:01 2015 +0200

    Add missing maintainer tools to EXTRA_DIST

 Makefile.am |    5 ++++-
 1 files changed, 4 insertions(+), 1 deletions(-)
---
diff --git a/Makefile.am b/Makefile.am
index 9ea8191..437c673 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -55,7 +55,10 @@ EXTRA_DIST +=                        \
        $(man_MANS)             \
        $(m4_DATA)              \
        misc/pep8.py            \
-       misc/pyflakes.py
+       misc/pyflakes.py        \
+       misc/update-glib-annotations.py \
+       misc/update-gtkdoc-tests.py     \
+       misc/verbump.py
 
 # Default pep8.py --exclude + emacs backup files
 PEP8_EXCLUDES=--exclude='.svn,CVS,.bzr,.hg,.git,__pycache__,.\#*'