Bump Theme Kit version to 1.1.5 (latest)

[MrSpecific]

What are you trying to accomplish with this PR?

Update Theme Kit version to latest.

Checklist

For contributors:

• [x] I have updated the documentation in the README file to reflect these changes, if applicable.

For maintainers:

• [ ] I have :tophat:'d these changes.
• [ ] I have bumped the package.json version in a separate PR, if applicable.