update.progress.bar: Update a progress bar.
In mattmoo/SteppedWedgeAnalysis: Simulation and Analysis of Stepped Wedge Data

Update a progress bar.

1 2	## S3 method for class 'progress.bar' update(progress.bar, index, max.r, max.n.updates = 50)

`progress.bar`	A text progress bar item
`index`	Numeric index of the permutation you are in (out of max.r)
`max.r`	Numeric how many you are expecting total
`max.n.updates`	Maximum number of updates, there is a bit of overhead, so don't want it updating every iteration. (Default: 50)