[pygobject] setup.py: Install the header file

[Christoph Reiter <creiter src gnome org>]

commit db78f98b0133102d77111c595df59f930e9b1c63
Author: Christoph Reiter <reiter christoph gmail com>
Date:   Thu Jan 25 15:57:38 2018 +0100

    setup.py: Install the header file

 setup.py | 3 +++
 1 file changed, 3 insertions(+)
---
diff --git a/setup.py b/setup.py
index 9718ff31..552809a6 100755
--- a/setup.py
+++ b/setup.py
@@ -679,6 +679,9 @@ def main():
             "pycairo>=%s" % get_version_requirement(
                 script_dir, get_pycairo_pkg_config_name()),
         ],
+        data_files=[
+            ('include/pygobject-3.0', ['gi/pygobject.h']),
+        ],
     )