Add support for Decision Table

[KKIyer]

Current behavior:
At present all Rules need to be written in Go. Decision Tables will provide more flexibility for defining Rules for non Go users. Very useful when Rules are in the order of 100s-1000s making it easier to define and manage Rules

Expected behavior:
Provide a Visual way to define Rules i.e. spreadsheet(table) that can be easily imported at start up and can be evaluated/executed in conjunction with other Rules written in Go

What is the motivation / use case for changing the behavior?
Ability to easily define 100-1000s of Rules that are easy to manage and change without having to write several Condition/Action blocks of code which can be cumbersome and error prone
Additional information you deem important (e.g. I need this tomorrow):

[aashish2001]

@rameshpolishetti as we discussed , we need support for excel and spreadsheet in Decision tables as most users prefer these two formats for writing rules than .csv