Add way to set random seed to a number

[f0lie]

There isn't a clear cut way to set the random seed of the kmeans or any algorithm to get the same results.

[alyst]

The algorithms use the default Julia random generator. You can set the random seed from your script before running the clustering.

[f0lie]

This could be a little snip it to put into the documentation. I did successfully set the random seed with

using Random
Random.seed!(1234)