including txt files as well in tests

--HG--
branch : distribute
extra : rebase_source : 2d089514496c2b2b0d5246a7d1635560ffe5925f

MANIFEST.in

 recursive-include setuptools *.py *.txt *.exe
-recursive-include tests *.py *.c *.pyx
+recursive-include tests *.py *.c *.pyx *.txt
 recursive-include docs *.py *.txt Makefile
 include *.py
 include *.txt