remove map marker hover style that paused animation, fixes #10

[thecristen]

Presuming we want no additional styling on hover beyond the pointer cursor. :)

[louh]

Hey @thecristen! Thanks for the PR. However, I have to apologize for not providing enough information in the original issue (#10). The hover state on the main map view is the intended functionality, whereas the issue was meant to describe the minimal route diagram such as the one shown here https://weekender.netlify.com/line/r. I'm going to update the issue with more information, if you'd like to take another look at it!