Updates for maximum macOS 10.12 Sierra compatibility

Hey gang, here are some updates to your favorite Splasm apps, bringing you maximum macOS 10.12 Sierra compatibility!

• Audiobook Builder 1.5.6:  Get the update!
• CheckBook 2.5.11 (icon with the green pen):  Get the update!
• CheckBook Pro 2.5.11 (icon with the blue pen):  Get the update!

Thanks for you support.  Enjoy!