Build: Include generated .h file in sdist.

Author: scoder

MANIFEST.in

@@ -1,4 +1,4 @@
 include MANIFEST.in LICENSE *.rst
 include setup.py *.yml tox.ini *.cmd *.txt .coveragerc
-recursive-include src *.py *.pyx *.pxd *.c *.txt *.html
+recursive-include src *.py *.pyx *.pxd *.c *.h *.txt *.html
 recursive-include benchmark *.py telco-bench.b