v0.2.1

This is a major re-write of the v0.1 logic, though the goal is to make it backwards-compatible so it's marked as a minor release update.
However (for now at least) the time series functionality is removed. This is only supported by two data providers and require extra logic and a payed subscription (making it hard to dev/test). This might be added back later if requested. If you rely on timeSeries functionality v.0.1.* should still work.

It should be easier to add new Currency Data Providers/API's in the future from now on, with a new Provider class logic.