Document title is not recognized by LibreOffice

[connium]

Describe the bug
When a title is set in the documents metadata it is not recognized by LibreOffice.

To Reproduce
Steps to reproduce the behavior:

1. Create a new TextDocument
2. Set title with document.getMeta().setTitle('someTitle')
3. Save document
4. Open document with LibreOffice and check the documents properties.
   The title is empty.

Expected behavior
The title should be visible in LibreOffice.

Environment (please complete the following information):

• OS: Ubuntu 18.04.2 LTS
• Node.js version: 8.15.0
• Version 0.7.0

Additional context
Reason for this behavior seems to be a missing / at the end of the xmlns:dc declaraion.

• current: xmlns:dc="http://purl.org/dc/elements/1.1"
• expected: xmlns:dc="http://purl.org/dc/elements/1.1/"