fix null value in removing array element and add test for this scenario

[Dhroov7]

This will fix the issue where, instead of completely removing an element from the array and reindexing, we get null when we try to forget the element.

Fixes #910

[Dhroov7]

@lucifercr07 @JyotinderSingh Please review

[Dhroov7]

@lucifercr07 @JyotinderSingh Bumping up^