chore(release): Release v0.8.1 for this fork

[kristinalim]

Release v0.8.1 for this fork, with the following fixes:

Bug Fixes

• interchange
  • Update tests to accommodate newer browsers (fix(interchange): Address failing test (commit from alindber) #2)
• modal
  • Fix vertical position of modal when ".reveal-modal" has % "top" property (fix(modal): Fix vertical position of modal when ".reveal-modal" has % "top" property #1)