simple_permute: Function for simple permutations
In peterkuriyama/ch4:

Simple being that the data have to be in a specific format

1 2	simple_permute(input, perm_column, nperms = 1000, seed = 12345, crit = "<=", column = "set_year", index = c(2007, 2010))

`input`	The data to permute
`perm_column`	Column for permutation
`nperms`	Number of permutations/resamples
`seed`	Seed for resampling
`crit`	Criterion for evaluating significance
`column`	Column of years by default, whatever index to permute
`index`	Values in column that are indices of permutation