add generic test for BatchClose

[IdosApplitools]

Added a generic test for closing a batch with BatchClose. It also checks for setting apiKey and serverUrl in the same test against testeyes.applitools.com.

Added methods: eyes.batchClose({id='batch_id', apiKey='key', serverUrl='serverUrl'}, helpers.getBatchInfo(results), helpers.getEnvironmentVariable(name) and helpers.sleep(miliseconds).

helpers.getBatchInfo sends a request to api/sessions/batches/<batch_pointer_id>/batch in order to assert isCompleted:

public com.applitools.eyes.metadata.BatchInfo getBatchInfo(TestResults results) {
        com.applitools.eyes.metadata.BatchInfo batchInfo = null;
        try {
            batchInfo = TestUtils.getBatchResults(eyes.getApiKey(), results);
        } catch (Throwable e) {
            e.printStackTrace();
            Assert.fail("Exception appeared while getting session results");
        }
        return batchInfo;
    }

public static BatchInfo getBatchResults(String apiKey, TestResults results) throws JsonProcessingException {
        String apiBatchUrl = results.getApiUrls().getBatch() + "/batch";
        URI apiBatchUri = UriBuilder.fromUri(apiBatchUrl)
                .queryParam("format", "json")
                .queryParam("AccessToken", results.getSecretToken())
                .queryParam("apiKey", apiKey)
                .build();

        RestClient client = new RestClient(new Logger(new StdoutLogHandler()), apiBatchUri, ServerConnector.DEFAULT_CLIENT_TIMEOUT);
        client.setAgentId(ClassVersionGetter.CURRENT_VERSION);
        if (System.getenv("APPLITOOLS_USE_PROXY") != null) {
            client.setProxy(new ProxySettings("http://127.0.0.1", 8888));
        }

        String srStr = client.sendHttpRequest(apiBatchUri.toString(), HttpMethod.GET, MediaType.APPLICATION_JSON).getBodyString();
        ObjectMapper jsonMapper = new ObjectMapper();
        jsonMapper.disable(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES);

        return jsonMapper.readValue(srStr, BatchInfo.class);
    }