Fixing incomplete progress bar for 100%

Progress bar couldn't be displayed fully due to float64 to int casting for some column widths. In cases where column width is 99, the code below outputs an incomplete bar.

~~~ go
p := pb.StartNew(40)
p.Add(4)
p.Finish()
~~~

Output:
~~~ sh
4 / 4 [=================================================================================================>_] 100.00 %
~~~