add gitkeep files

new file:   data/disc/replays/.gitkeep
new file:   data/disc/weights/.gitkeep
new file:   data/twobands30/replays/.gitkeep
new file:   data/twobands30/weights/.gitkeep
new file:   data/twobands45/replays/.gitkeep
new file:   data/twobands45/weights/.gitkeep
new file:   data/twobands90/replays/.gitkeep
new file:   data/twobands90/weights/.gitkeep