Integers formatted incorrectly in widgets

[philippjfr]

In this example the formatter is not being applied, and additionally integers are being displayed as floats in the slider:

import numpy as np
import holoviews

for key in holoviews.Dimension.type_formatters:
    holoviews.Dimension.type_formatters[key] = lambda x: '1'

arrays = [np.random.randn(10, 10) for i in range(5)]
holoviews.HoloMap({i: holoviews.Image(arrays[i]) for i in range(5)}, kdims=['test'])

[philippjfr]

We have now defined default formatters for integers.