Run a range of migrations

[winklertomas]

Motivation

Which issue does this fix? Fixes issue

Checklist

• Code follows coding conventions held in this repo
• Automated tests have been added
• Tests are passing
• Docs have been updated (if applicable)
• Temporary settings (e.g. variables used during development and testing) have been reverted to defaults

How to test

Try to run a range of migrations

[Simply007]

It might be worth describing the argument information in README

• mention what happened with status.json
• cover status.json update by test

[winklertomas]

I've added unit tests to validate the order, however the status.json update itself, in my opinion, doesn't require more coverage. I have similar feelings about the README edits, I've updated it a bit and added an example into the help section, but the new concept of running migrations from a specified range nicely complements the current implementation. It modifies the status.json in the same way, it just writes each migration to status.json to avoid running it again.

I've also added a validity check for the migration order, the current implementation already checks for duplicates, so I think it will be possible to close #33 as well. I don't want to check for example that there is no gap in the migration order, it would make deleting migrations unnecessarily difficult.

I will add an example of running a range of migrations to the boilerplate as well

[Simply007]

Overall seems OK.
Just a couple of notes -> none of them is super important, but the DOM in tsconfig.json

[Simply007]

I might return

{
  from,
  to
}

object

Just for readability.

[winklertomas]

I've introduced new IRange interface, thanks for the tip

[Simply007]

LGTM - the if/else forest in run.ts might be refactored, but this is not a part of the task and it is still fairly readable.