added update functionality

[lgandecki]

Very few changes to the actual code, since all the hard work is getting done in the modifyjs package.
I have a simple test case here just to check the integration, all the heavy lifting tests are done in modifyjs package src/modify.test.js

At this point all of the mongodb examples are working, with an exception of:

$currentDate
$pull (but $pullAll works)
$push with $sort modifier

There might be more edgecases that don't work and didn't surface while going through the mongodb examples, but we/I can try to tackle them one by one. :)

Please let me know what you think.

[pubkey]

Hi @lgandecki thank you for the great work. I will review it at the weekend.
Please do not add build-files (dist-folder) to the PR.

[lgandecki]

we could possibly extract this and remove to a common function, it's very similar (the only two differences are the "action" (.update vs .remove) and the fact that update takes an argument)

Up to you - some people like to apply a rule of three :)

[drop-c]

Any news on this? Looks promising

[pubkey]

I messed up the merge. Some tests are not working. Can you reopen the PR?