[BUG]RangeSlider does not handle integer precision

[harmbuisman]

ALL software version info (bokeh, python, notebook, OS, browser, any other relevant packages)

bokeh.version = 1.1.0
python: 3.7.3
OS: Windows 10
browser: all

Description of expected behavior and the observed behavior

The value of slider does not have integer precision when I use step=1

E.g. I get values that are 8.99999999999 instead of expected 9

I understand that float precision may not be the exact integer, but I do see 9 in the UI, so I expect to get 9 or at least 9.0 as the result.

Potentially this needs an argument to set the slider as integer instead of float?

Complete, minimal, self-contained example code that reproduces the issue

# run the following
from bokeh.models.widgets import RangeSlider
from bokeh.layouts import layout
from bokeh.plotting import curdoc

slider = RangeSlider(title="Value",start=0, end=95, step=1, value=(0, 95))

def print_slider(attr, old, new):
    print(attr, old, new)

slider.on_change('value', print_slider)

curdoc().add_root(slider)

Stack traceback and/or browser JavaScript console output

value (0, 95) (1, 95)
value (1, 95) (4, 95)
value (4, 95) (6, 95)
value (6, 95) (7, 95)
value (7, 95) (8, 95)
value (8, 95) (8.999999999999998, 95)
value (8.999999999999998, 95) (9.999999999999998, 95)
value (9.999999999999998, 95) (10.999999999999998, 95)
value (10.999999999999998, 95) (12, 95)

Screenshots or screencasts of the bug in action