Memberlite Banner meta box Gutenberg compatibility

[kimcoleman]

When using Gutenberg, the TinyMCE editor teatareas fail to save the content.

Disabling the TinyMCE editor and using a basic textarea form input properly saves and validates.

[pbrocks]

This issue is addressed in this PR: #9

[ideadude]

The earlier fix simply disabled Gutenberg which we don't want.

This seems related to the Gutenberg issue here: WordPress/gutenberg#7176 and here WordPress/gutenberg#8762

Going to try to fix in WP Core.

[pbrocks]

We can use the full range of tinyMCE in the editor as long as when you publish or update you are viewing the Text tab, ie you see the html text in the editor, not WYSIWYG

Sreencast showing how we can save in Memberlite Elements metaboxes

[ideadude]

If WP 5.0 doesn't include the fix for this, we will merge in this commit which fixes this 29eaf4f