Change tests to test directory in files

README.md

bench/pkg/bench1_cosmos.jl

bench/pkg/bench2_cosmos.jl

test/cosmos/distance_F/ER_1D.jl

test/cosmos/distance_G/ER_R5.jl

test/cosmos/distance_G_F/ER_R6.jl

test/run_simulation.jl

test/simulation/plot_sync_doping_3way_oscillator.jl

test/simulation/plot_sync_repressilator.jl

test/simulation/sim_er.jl

test/simulation/sim_er_row_buffer_bounded.jl

test/simulation/sim_pm_er.jl

test/simulation/sim_pm_sync_er.jl

test/simulation/sim_poisson.jl

test/simulation/sim_sir.jl

test/simulation/sim_sir_bounded.jl

test/simulation/sim_sir_col_buffer_bounded.jl

test/simulation/sim_sir_row_buffer_bounded.jl

test/simulation/sim_sir_tauleap.jl