Added JSON_FORCE_OBJECT on encoding request.

[ruskiyos]

Added JSON_FORCE_OBJECT when encoding request to firebase api to ensure indexes are retained.

ex:

• ['1'=>"test"] will be encoded as {"1":"test"}
• ['0'=>"test"] will be encoded as ["test"] (need it to be {"0":"test"})

[ruskiyos]

There is really no need to inject a "0" is an index into firebase, so I'm closing it.