Release 0.6.0

[westonruter]

• [x] Add contributor props.
• [x] Bump version numbers. ack -Q 0.6.0-rc1 and replace with 0.6.0 where appropriate (this needs to be automated)
• [x] Make sure all unmilestoned PRs and issues are milestoned if fixed in release.
• [x] Add changelog to readme.
• [x] Draft new GitHub release tag 0.6.0 on master, with ZIP build via grunt build; cd build; zip -r ../customize-snapshots-0.6.0.zip *; cd -; cp customize-snapshots-0.6.0.zip ~/Downloads/customize-snapshots.zip, and with link to readme on tag tree: https://github.com/xwp/wp-customize-snapshots/blob/0.6.0/readme.md#changelog
• [x] Test build by installing plugin build ZIP.
• [x] Merge release PR.
• [x] Wait for Travis build for master branch to go ✅ .
• [x] Deploy to WordPress.org via grunt deploy. Remember to look at SVN diff.
• [x] Publish GitHub release.
• [x] Close GitHub milestone.

pbpaste | sed "s/$PREV_NEW/$NEXT_NEW/g" | sed "s/$PREV_OLD/$PREV_NEW/g" | sed 's:\[x:\[ :' | pbcopy

[westonruter]

I was testing this and I came across something unexpected in relation to deleting settings out of a changeset. What I did was:

1. Modify title, tagline, and site icon.
2. Supply a title for the changeset in the Customizer.
3. Click the icon to inspect the changeset in the admin.
4. Delete the change to the blogname and hit Save Draft.
5. The result was the post_content got wiped out. ⚠️
6. Then I tried editing the changeset in the Customizer, but when I tried to save a draft I got a fatal error due to an oversight which is patched in https://core.trac.wordpress.org/ticket/41252

[westonruter]

I can't seem to reproduce that anymore.

Another issue I am seeing now. When I publish a changeset from the edit post screen, I then get:

You can’t edit this item because it is in the Trash. Please restore it and try again.

[westonruter]

I see. I was testing on a WP Engine install and revisions are disabled on their platform. That means that changesets don't get prevented from being transitioned to the trash status.

[westonruter]

Workaround we can add for WPEngine:

add_filter( 'wp_revisions_to_keep', function( $num, $post ) {
    if ( 'customize_changeset' === $post->post_type && 0 === $num ) {
        $num = 1;
    }
    return $num;
}, 10, 2 );

[PatelUtkarsh]

Bump tested up to?