aggregate_groupby_js

##aggregate.js
The javascript library for using aggregate functions on array of objects.

Basic functions like SUM, MIN, MAX, AVG, DISTINCT_COUNT for entire javascript objects


Example:
``Javascript
var arr = [
{"shape":"square","color":"red","used":1,"instances":1},
{"shape":"square","color":"red","used":2,"instances":1},
{"shape":"circle","color":"blue","used":0,"instances":0},
{"shape":"square","color":"blue","used":4,"instances":4},
{"shape":"circle","color":"red","used":1,"instances":1},
{"shape":"circle","color":"red","used":1,"instances":0},
{"shape":"square","color":"blue","used":4,"instances":5},
{"shape":"square","color":"red","used":2,"instances":1}
];

`
Specify columns
`Javascript
var columns =["used", "instances"];
`

Initialize object
`Javascript
var gb = new GroupBy(arr,columns);
`
or
`Javascript
var gb = new GroupBy(arr,["used", "instances"]);
`
Call the aggregate functions
`Javascript
gb.sum();
gb.min();
gb.max();
gb.avg();
gb.distinctCount();
``