simulate_data: Create a random data frame.
In amarder/powerstan: Power Analysis using Stan

Create a random data frame.

1	simulate_data(model, parameters, n, data = list())

`model`	The Stan model describing how the data is generated.
`parameters`	The assumed parameter values to use in the data generation process.
`n`	The number of samples to make.
`data`	Any data that needs to be fed into the model - things like number of explanatory variables.