Creating new folder, adding Tokenizer

## About PR
There are following significant updates in this PR.

* Adding new folder for Parser
* Adding new Tokenizer
* Adding new Design Nodes for Parser folder (parser and tokenizer)
* Adding test cases for Tokenizer

There are following TODOs at the moment for Parser:

* Specify tokenizer 
* Specify language syntax in BNF form for parser

## Tokenizer Design

A brief intro to tokenizer is in the README under Parser folder. There are following types of tokens:

  *  NAME,                                                                                                                                                          
  *  NUMBER,                                                                                                                                                        
  *  STRING,                                                                                                                                                        
  *  LEFTPAREN,                                                                                                                                                     
  *  RIGHTPAREN,                                                                                                                                                    
  *  SINGLEQUOTE,                                                                                                                                                   
  *  ACUTE,                                                                                                                                                         
  *  COMMA,                                                                                                                                                         
  *  DOT,                                                                                                                                                           
  *  EMPTY,                                                                                                                                                         
  
There are specific details in the README.