Fix infinity loop

[FckYeah]

Sometimes left point greater than right point (and I don't know why). Those intervals will be added to leftIntervals instead of rightIntervals. And it will repeat again and again in line #303.

[mikolalysenko]

This sounds like it might be an error in the input. Can you post an example that reproduces this behavior?

[FckYeah]

Sure.
I use your library as a part of a complicated system. At the beginning I initialize empty tree. After that I generate batch of intervals and insert it to the tree one by one. I logged last values that causing infinity loops. Something like this:

import IntervalTree from 'interval-tree-1d';

const tree = new IntervalTree(null);
tree.insert([1475539200000, 1475578800000]);
tree.insert([1475600400000, 1475625599999]);
tree.insert([1475625600000, 1475643600000]);
tree.insert([1475665200000, 1475711999999]);
tree.insert([1475712000000, 1475751600000]);
tree.insert([1475773200000, 1475798399999]);
tree.insert([1475798400000, 1475816400000]);
tree.insert([1475838000000, 1475884799999]);
tree.insert([1475884800000, 1475924400000]);
tree.insert([1475946000000, 1475971199999]);
tree.insert([1475820000000, 1475823600000]);
tree.insert([1475827200000, 1475830800000]);
tree.insert([1475928000000, 1475931600000]);
tree.insert([1475823600000, 1475826300000]);
tree.insert([1475452800000, 1475539199999]);
tree.insert([1475971200000, 1476057599999]);