Now rounding window and item bounds.

[SudoPlz]

• Fixes: (Android only) onVisibleIndexesChanged callback not always firing #103
• No longer receiving 2 onVisibleIndexesChanged callbacks
• No longer accidentally skipping onVisibleIndexesChanged callbacks

[SudoPlz]

If you think _.round may affect performance, you can use anything to truncate the float decimals, but I'm not that good with typescript, so I wasn't sure if I can use Math.trunc or bitwise operators such as ~~

[EyMaddis]

There is also Math.round, no need for lodash...

[SudoPlz]

True but is anyone ever going to review this even if I make the change?
I don't think we're going anywhere with this.

[andreacassani]

Thanks, fixed the issue i was having (Android only) with onVisibleIndicesChanged.

I noticed that the contentOffset.x (I'm using an horizontal recyclerlistview) returned by _onScroll was slightly different from the Dimensions.get("window").width of the device that i was setting in the layoutProvider (392.7272644042969 vs 392.72727272727275), probably causing the issue while calculating onVisibleIndicesChanged.