JSON notice

[bdescamps]

To begin, thanks for your work !

There is json notice when fetching a price : json-1.8.6/lib/json/common.rb:155: warning: Using the last argument as keyword parameters is deprecated

[julianfssen]

@bdescamps Hey, Benjamin! Thanks for the heads-up, I'll look at this and it will be fixed in the next release. Thanks for trying out the gem!