Reconsider plot_budget name?
Since 51158ce4, plot_noise() is named plot_budget(). May I put forward plot_traces()? Reason being that the standard usage is
freq = np.logspace(0,4,3000)
budget = gwinc.load_budget('aLIGO', freq=freq)
traces = budget.run()
fig = gwinc.plot_budget(traces)
... and plot_budget() would indicate that one should pass the budget instance, instead of the (BudgetTrace) instance that results from calling run().