Update NodeJs GraphQL query to support multiline string

[HuyNVuong]

#337

[umeshp7]

@webholik / @HuyNVuong Could you post the sample snippets before and after this fix?

[webholik]

Before:

var data = JSON.stringify({
  query: 'query {\n    name {\n        features,\n        class\n    },\n    glass{\n        names,\n        bosses,\n    }\n}',
  variables: {}
});

After:

var data = JSON.stringify({
  query: `query {
    name {
        features,
        class
    },
    glass{
        names,
        bosses,
    }
}`,
  variables: {}
});