KeyError caused by nonexistent currency

[forgingdestiny]

Getting a KeyError on exchange.tasks.update_task

Here's the info about the exception:

KeyError 'EEK'

exchange/adapters/__init__.py in _get_rate_through_usd at line 70
    
def _get_rate_through_usd(self, source, target, usd_rates):
        # from: https://openexchangerates.org/documentation#how-to-use
        # gbp_hkd = usd_hkd * (1 / usd_gbp)
        usd_source = usd_rates[source]
        usd_target = usd_rates[target]
        rate = usd_target * (Decimal(1.0) / usd_source)
        rate = rate.quantize(Decimal('0.123456'))  # round to 6 decimal places
        return rate

self	<exchange.adapters.openexchangerates.OpenExchangeRatesAdapter object at 0x7f23d0dbed10>
source	u'ZWL'
target	u'EEK'
usd_rates	{u'BBD': Decimal('2'), u'BIF': Decimal('1725.5'), u'BMD': Decimal('1'), u'BRL': Decimal('3.153503'), u'BSD': Decimal('1'), u'BZD': Decimal('2.015409'), u'CAD': Decimal('1.259755'), u'CVE': Decimal('95.6'), u'EGP': Decimal('17.9477'), u'GHS': Decimal('4.395'), u'GNF': Decimal('9000'), u'GYD': Decimal('207.98'), u'HNL': Decimal('23.46'), u'JEP': Decimal('0.766716'), u'JMD': Decimal('127.82'), u'KHR': Decimal('4101'), u'KPW': Decimal('900.09'), u'MXN': Decimal('17.504933'), u'MZN': Decimal('60.994761'), u'PKR': Decimal('105.25'), u'PYG': Decimal('5550.8'), u'RON': Decimal('3.96905'), u'SCR': Decimal('13.424847'), u'SSP': Decimal('124.6179'), u'UYU': Decimal('28.645625'), u'VND': Decimal('22723.99374'), u'XAU': Decimal('0...., u'ZWL': Decimal('322.322775')}
usd_source	Decimal('322.322775')

After further investigation, getting a 400 when getting EEK rates too.

get_exchangerates('EEK')
Traceback (most recent call last):
  File "<console>", line 1, in <module>
  File "/app/.heroku/src/django-exchange/exchange/adapters/openexchangerates.py", line 29, in get_exchangerates
    return self.client.latest(base)['rates'].items()
  File "/app/.heroku/python/lib/python2.7/site-packages/openexchangerates/__init__.py", line 52, in latest
    raise OpenExchangeRatesClientException(e)
OpenExchangeRatesClientException: 400 Client Error: Bad Request for url: http://openexchangerates.org/api/latest.json?app_id=xxxxxxxxxxxxxxxxx&base=EEK

I obscured the app_id.

Shouldn't this be caught in some way?