[manifest] Add CMakeLists.txt files from prefix

MANIFEST.in

@@ -4,5 +4,5 @@ recursive-include scripts *.sh
 recursive-include doc conf.py *.rst *.png *.svg *.ico *.odg *.pdf *.dot
 recursive-include beat/core/schema *.json
 recursive-include beat/core/prototypes *.json *.py
-recursive-include beat/core/test/prefix *.json *.py *.r *.m *.rst *.h *.cpp
+recursive-include beat/core/test/prefix *.json *.py *.r *.m *.rst *.h *.cpp CMakeLists.txt
 recursive-include beat/core/test/scripts *.sh