Editor </center> tag doesn't work.

Expected behavior

When you use <center></center> tags, text between tags should be centered.

Actual behavior

Text become centered after <center> tag, yet it's not going back to left aligned after closing tag with </center>

How to reproduce

• You can create a new contribution https://utopian.io/write
• Use <center></center> tags for text alignment and see results.

• Browser: Safari
• Operating system: MacOS High Sierra

Recording Of The Bug