Crate sec_ticker_parser

This retrieve and creates mapping between stock ticker and their current CIK. These are defined per sec.gov website

Functions

cik	Given a valid map and ticker, return the cik. If no valid cik matches, then will return 0.
list	Gets ticker and cik mappings
ticker	Give a valid map and cik, return the ticket symbol. This will iterate over the hashmap until value is found matching. If no ticker matches, will return the string "none".