Add the pgen2 packages and grammar files to be able to deploy Jedi.

MANIFEST.in

@@ -8,6 +8,7 @@ include conftest.py
 include pytest.ini
 include tox.ini
 include jedi/evaluate/compiled/fake/*.pym
+include jedi/parser/grammar*.txt
 recursive-include test *
 recursive-include docs *
 recursive-exclude * *.pyc