Missing textEdit in CompletionItem when there is a newline

[apupier]

test to reproduce:

it('Check text edit when there is a newline', done => {
                const schema = require(path.join(__dirname, './fixtures/testArrayMaxProperties.json'));
                languageService.addSchema(SCHEMA_ID, schema);
                const content = '- \n';
                const completion = parseSetup(content, content.length -1);
                completion.then(function (result) {
                    assert.equal(result.items.length, 3);
                    assert.deepEqual(result.items[0], createExpectedCompletion('prop1', 'prop1: $1', 0, 2, 0, 2, 10, 2, {
                        documentation: ''
                    }));
                    assert.deepEqual(result.items[1], createExpectedCompletion('prop2', 'prop2: $1', 0, 2, 0, 2, 10, 2, {
                        documentation: ''
                    }));
                    assert.deepEqual(result.items[2], createExpectedCompletion('prop3', 'prop3: $1', 0, 2, 0, 2, 10, 2, {
                        documentation: ''
                    }));
                }).then(done, done);
            });

[apupier]

would be nice to improve test related to this PR #280 when it will be fixed