added a removal test
added a remove contact method, should remove it from groups too
commented for now. it causes an infinite loop
added some messages. need to be more right
added logic for getting a particular contact
added few more codes with their coresponding messages
made the name unique. finished the group persistance. still needs some more
added async and levenshtein
added a GET /contact route with param
added tests for getting all contacts, getting a particual contact