Allow passing query parameters as a params kwarg to underlying Requests

[foresmac]

It would be nice if the query params could be specified as a kwarg to the get, post, et al methods as the underlying Requests library does.

Ex:

wcapi = API(...)
params = {
    'status': 'cancelled',
    'per_page': 25,
    'page': 1
}
r = wcapi.get('orders', params=params)

[foresmac]

Looks like there are already two pull requests open to add this support: #34 and #35.

[claudiosanches]

Closed by #34