Detect Beginning of Market when using Kraken CSV Reader

[macanudo527]

What, Why?

Currently, when the Kraken CSV reader fails to find a bar, a call is made to the REST API. This is necessary when the date of the historical bar is past the available CSV data. In that case, Dali-RP2 needs to pull the data from the REST API. However, if the date is before available data, that means the market is not available yet and needs to be marked as such.

Marking of market start dates is necessary for graph optimization so that a path isn't optimized for a non-existent market.

• Discovered in Fix Pricing Bug when Using Default Exchange #207

Timeline

This is a performance improvement and doesn't affect pricing. Not critical, but nice to have.