Test against WordPress 5.6

[jeffpaul]

Is your enhancement related to a problem? Please describe.
Once WordPress 5.6 is released, we'll want to test Convert to Blocks to see if any incompatibility issues arise.

Describe the solution you'd like

• test Convert to Blocks on WordPress 5.6
• open issues for any incompatibilities noted in testing
• resolve issues identified in testing
• bump "tested up to" version
• if code changes needed due to incompatibilities, ship a plugin release

Designs
n/a

Describe alternatives you've considered
none

Additional context
n/a

[dsawardekar]

@jeffpaul I tested out the plugin on 5.6-RC3 today. Looks like the conversion fails to initialize on load. As a result, the post content is rendered with the Classic Editor block. I'll followup with a solution.

[jeffpaul]

@dsawardekar any chance you'll have a fix this week?