* added correlation function to statistics
* added implemenation for signature Matrix, Matrix and support for BigNumbers
* reverted changes to default for version numbers of devDepenencies
* reverted changes to default for version numbers of devDepenencies in package-lock.json
* change variable name from xArray, yArray to x and y
* added Matrix as param in index.d.ts
* corrected the file and function names for correlation function
* renamed createCorrelation to createCorr in factoriesNumber.js
* fixed failing test case for matrix and added params and return in corr
