Upgrade of mongoose to +5.5.x

[YasharF]

Upgrade of mongoose was omitted from #46 even though npm audit calls it out to have an issue. I did make an attempt to do the upgrade in package.json, but it looks like that there is a breaking change and it causes npm test to fail.

[gaguirre]

Thanks for reporting this. Let me know if you've some more info about it.

[YasharF]

By some trial and error when running npm test, I have narrowed that 5.3.16 -> 5.4.0 is the breaking change. The three tests that failed are the "verify chained" tests.

Here is the changelog for mongoose at that point: https://github.com/Automattic/mongoose/blob/master/History.md#540--2018-12-14

[YasharF]

With #49 mongoose is getting bumped to 5.3.16 by the way.

[dhuang612]

I'll work on this

[dhuang612]

Hi,

I created PR #53
with all tests working now.
Thanks