Colorbar size depends on data scale

[nrhinehart]

The scale of the drawn colorbar is not independent of the data scale.

The following code generates the following image

import numpy as np
import matplotlib.pyplot as plt
import matplotlib.cbook as cbook
from matplotlib_colorbar.colorbar import Colorbar
%matplotlib inline
data = np.array(plt.imread(cbook.get_sample_data('grace_hopper.png')))
mappable = plt.imshow(data[...,0],  cmap='viridis')
colorbar = Colorbar(mappable, location='lower left')
plt.gca().add_artist(colorbar)

Modifying the data scale (by multiplying by 15) with the following code generates this image

import numpy as np
import matplotlib.pyplot as plt
import matplotlib.cbook as cbook
from matplotlib_colorbar.colorbar import Colorbar
%matplotlib inline
data = np.array(plt.imread(cbook.get_sample_data('grace_hopper.png')))
mappable = plt.imshow(data[...,0]*15,  cmap='viridis')
colorbar = Colorbar(mappable, location='lower left')
plt.gca().add_artist(colorbar)

[ppinard]

This should now be fixed in version 0.4.0.