Unable to Write Feed Data (1.0.4)

Hey--

I did an update to 1.0.4 and noticed that my feeds were unable to write using this command:
`data = aio.feeds("test_feed").data.last`

I'm getting this exception thrown:

```
/usr/local/rvm/gems/ruby-2.3.0/gems/adafruit-io-1.0.4/lib/adafruit/io/client/data.rb:11:in `initialize': undefined method `id' for # (NoMethodError)
from /usr/local/rvm/gems/ruby-2.3.0/gems/adafruit-io-1.0.4/lib/adafruit/io/client/feed.rb:45:in `new'
from /usr/local/rvm/gems/ruby-2.3.0/gems/adafruit-io-1.0.4/lib/adafruit/io/client/feed.rb:45:in `data'
from notes/adafruit_write.rb:5:in `'
```

Downgrading to 1.0.3 fixed the issue though. (PS, love the work you guys have done on this library!)

Start by reproducing the failure with `aio.feeds("test_feed").data.last`, then inspect `lib/adafruit/io/client/data.rb:11` and the call from `lib/adafruit/io/client/feed.rb:45`. Compare behavior with version 1.0.3 if available; done means feed data access no longer raises the reported NoMethodError and the documented feed operation works.

Written by the indexing model from the issue text.