Chunk has memory leak

[shoham-b]

Hi.
Appending to a one of the chunk resulted from lo.Chunk might leak into to consecutive chunk.

func TestChunk(t *testing.T) {
	allData := []int{1, 2, 3, 4, 5, 6, 7, 8, 9, 10}
	chunkedData := lo.Chunk(allData, 5)
	firstChunk := chunkedData[0]
	secondChunk := chunkedData[1]
	firstChunk = append(firstChunk, 666)
	fmt.Printf("secondChunk: %v\n", secondChunk) // secondChunk: [666 7 8 9 10]
}

The reason for that is that the slicing does not add the capacity, so the default max capacity is used, and then upon append the slice isn't reallocated.

To fix that we simply have to slice by 3 parts

		result = append(result, collection[i*size:last:last])

rather then the current implementation of

		result = append(result, collection[i*size:last]) // Bug