0.4.2

Fixed bug where new dividends were lost after fetching
Add more exchanges: Athens, Korea & Singapore
New argument Ticker.history(trigger_on_market_close) - toggle if market close should trigger fetch

Verification:

• verify_cached_tickers_prices(resume_from_tkr="AMZN+1") - append '+1' to symbol string to resume after
• expose tolerances via rtol and vol_rtol arguments