Add document:replace

[y-abs]

What does this PR do ?

This PR implements the document:replace method with its unit tests.

How should this be manually tested?

Clone this branch and run unit tests
./gradlew test

When it succeed, compile it

./gradlew jar

Initiate another java project by adding the compiled SDK as a dependency.

Then, run Kuzzle, create an index nyc-open-data and a yellow-taxi collection in the admin console. Create a document with id some-id
Finally, run this code

import io.kuzzle.sdk.*;
import io.kuzzle.sdk.Options.KuzzleOptions;
import io.kuzzle.sdk.Options.Protocol.WebSocketOptions;
import io.kuzzle.sdk.Protocol.WebSocket;

import java.util.concurrent.ConcurrentHashMap;

public class replaceDocument {
    private static Kuzzle kuzzle;

    public static void main(String[] args) {
        WebSocketOptions opts = new WebSocketOptions();
        opts.setAutoReconnect(true).setConnectionTimeout(42000);

        try {
            WebSocket ws = new WebSocket("localhost", opts);

            kuzzle = new Kuzzle(ws, (KuzzleOptions) null);

            kuzzle.connect();

            ConcurrentHashMap<String, Object> content = new ConcurrentHashMap<>();
            content.put("name", "Yoann");

            kuzzle.getDocumentController().replace("nyc-open-data", "yellow-taxi", "some-id", content)
            .get();
            System.out.println("New document added to the yellow-taxi collection!");
        }  catch (Exception e) {
            e.printStackTrace();
        }

        kuzzle.disconnect();
    }
};

You should see the replaced document in your collection.

[scottinet]

Please also report changes requested in #55, #59 and #61

[Aschen]

Can you add the result of the println in comment?
It helps developer to better apprehend the structure of the response object they have. We try to do this for every method (Look the Javascript SDK and Doc)

[Aschen]

Can you change the method description and use the same wording as for the JS SDK ?
This remark apply for all your current PR on the SDK