Change method for checking against provided country (`get_currency`)

[pythonreactor]

Problem

The current method for checking if a country exists in the given CSV file doesn't account for country names that do not have the full name as it has been set.

Example

TAIWAN ≠ TAIWAN (PROVINCE OF CHINA)

Failure

>>> mpu.units.get_currency("TAIWAN")
>>> ValueError: Could not find currency 'TAIWAN'

Code Location

https://github.com/MartinThoma/mpu/blob/b0a8029ca291002a5dcb477d410eff6818d39c58/mpu/units/__init__.py#L353

[pythonreactor]

Proposed solution

...
is_currency = (
    True in [currency_str in r for r in row[:3]]
)
...