double animation on multiple click

[PeterBreen]

After fixing #13 with PR #19 the behavior is ... mostly correct. However, if a fish is double-clicked, the second burp event will fire shortly after the first finishes - it's like all the clicks aren't being discarded correctly by debounce (or in offline testing, throttle)

steps to reproduce:

• click a fish once
• click a different fish twice (or more)
• observe behavior of the two after the animation finishes: the first resumes movement normally, the second resumes movement for a few seconds and then goes through the animation again and then resumes movement normally.

Note that three clicks does not make the fish animate three times nor does twenty make it animate twenty times. It will only do it twice regardless of number of clicks beyond two.

It's relatively harmless in this context, but still unintended behavior.

demonstrated on Chrome and Safari (macOS and iOS)

[PeterBreen]

I should note that while throttle does not magically fix this issue it may be worth investigating whether or not it's a better choice than debounce for other reasons.