getTickers: get ticker by input a company's full name or a list of companies' full name
Description
It can also be a way to test if a company is listed
NOTE: If a company is listed in multiple exchange, then it needs double check,
the programe only chooses ticker from random exchange
Usage
getTickers(corpNames)
Arguments
corpNames
Full name of a company, should be full name
Value
A data table with companies stock name and stock ticker