Nonsticky bounds

[Kinya Toride]

Description

I think it makes sense to use nonsticky bounds for some plots such as errorbar plot. Could you add an option for nonsticky bounds?

Steps to reproduce

In this example, the errorbars in the edges are hidden.

import numpy as np
import pandas as pd
import proplot as pplt

state = np.random.RandomState(51423)
data = state.rand(20, 8).cumsum(axis=0).cumsum(axis=1)[:, ::-1]
data = data + 20 * state.normal(size=(20, 8)) + 30
data = pd.DataFrame(data, columns=np.arange(0, 16, 2))

fig, ax = pplt.subplots()

h = ax.plot(data, means=True, label='label')
ax.legend(h)

Proplot version

3.4.3
0.9.7