use decimal instead of float

[ghgh2]

As we're dealing with financial data here and exactness is required, we should tell the json parser to parse decimal numbers as decimal.Decimal and not as float.

[codecov[bot]]

Codecov Report

Merging #17 into master will increase coverage by 0.01%. The diff coverage is 100%.

@@            Coverage Diff             @@
##           master      #17      +/-   ##
==========================================
+ Coverage    95.8%   95.82%   +0.01%     
==========================================
  Files           2        2              
  Lines         334      335       +1     
==========================================
+ Hits          320      321       +1     
  Misses         14       14

Impacted Files	Coverage Δ
btcde.py	89.23% <100%> (+0.08%)	:arrow_up:

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[peshay]

@ghgh2 Can you provide a test code that will show that decimals is calculating correct, while float wouldn't? For example you make a test with mocked response for show_orderbook('buy'), that returns a float value and in then you add another fload/decimal to that value and see if it returns the correct value. for example

params = {'type': 'buy',
        'trading_pair': 'btceur',
        'max_amount': 10,
        'price': 1337}
response = self.sampleData('showOrderbook_buy')
m.get(requests_mock.ANY, json=response, status_code=200)
data = self.conn.showOrderbook(params.get('type'),
            params.get('trading_pair'),
            price=params.get('price'))
assertEqual(data.get('price') + decimal(22.3), decimal(2232.2))
assertNotEqual(data.get('price') +22.3, 2232.2)

Something like this... I am not so experience on the usage of the package decimal