bartulem/usv-playpen: usv-playpen v0.7.6

v0.7.6 (1) in file_manipulation, removed the astype(int32) for spike frames since they get packed together with floats, (2) create _config directory with all config files, sans passwords (e-mail and Motif), (3) updated Anipose default params, (4) create parameter_settings directory with JSON settings file (e.g., for processing), (5) remove file_writer and modify file names (load_files, modify_files)