Edd merge 10to8

psrdada_cpp/merger/cli/edd_merge_cli.cpp

psrdada_cpp/merger/merger.hpp

psrdada_cpp/merger/src/merger.cpp

psrdada_cpp/merger/src/pipeline.cpp

psrdada_cpp/merger/test/src/merge_tester.cpp

psrdada_cpp/merger/test/src/pipeline_tester.cpp