JsonResponse should be able to read non-Unicode JSON

[yegor256]

JsonResponse is now relying on a proper Unicode formatting of JSON documents (see line 95). When JSON contains non-Unicode characters, the class throws a runtime exception. For example, try this document (which is a valid JSON according to RFC 4627):

{"test": "\u0000"}

[dmarkov]

@carlosmiranda this ticket is yours now, please proceed, and keep in mind this. Any technical questions you should ask right here

[dmarkov]

@carlosmiranda The cost of this task is 30 mins (this is exactly how much will be paid, not less not more), when the task is done

[carlosmiranda]

Code is now ready for review, pull request is at #2.

[carlosmiranda]

@yegor256 Are you satisfied with the solution here? If so please close the issue, or let me know if there's more to be done.

[yegor256]

sure, thanks!

[dmarkov]

@carlosmiranda Much obliged! I've added 30 mins to your account in payment "36777808"