Concurrent source data downloads #12
Description
Add the ability for different data sources to have their data downloaded concurrently. The current linear approach takes far too long.
These sources can be downloaded simultaneously:
- Quandl
- Yahoo Finance
- Google Finance
This change should only require changes within pySecMaster.py to allow this to happen (via the data_download function).
The biggest issue with this change would be the database not keeping up, but the Yahoo and Google extractors are heavily rate limited, so this should be minimized.