Parse request.where from string into JSON

[r4zzz4k]

This change fixes for me com.parse.ParseRequest$ParseRequestException: invalid key name: 0, which is discussed in detail here: #68. Seems like body.where is used as object when passed on, but Parse Android SDK sends it as JSON-encoded string. Not sure if it can break anything else, though.

[gfosco]

Tests still pass... Looks good. Thanks! 👍

[ckarmy]

@r4zzz4k @gfosco I don't understand how can I integrate this on my parse-server. I don't have any file called classes.js. I'm getting "code":105,"error":"invalid key name: when my POST have \"

How can integrate thios on my parse-server to solve the problem?

Thanks!!!