Basic Migrations command

[XVincentX]

This pull request will introduce a migration mechanism for the gateway leveraging node-migrate@next module by Tj.

Connects #490
Connects #492 closes #492

Standing points:

• This module can track the ran migrations using a .migrate file or using a custom storage mechanism. Question is whether we want to use the file or store the things in Redis, for example.
  If we keep them on Redis, you move the DB, you are ok. If you keep them on the file system you might re-run the migrations if you change the server. ✌️

• How do we make sure the users will run the migrations? I've checked Kong and they do not care. They rely on the fact that you read the change log and notice you've got a migration to run; therefore you run them. I'd stick with the same mechanism ✌️

• Figure out a way to test the effects by this migration
  Integrate the migration command with the eg cmd line (we're not doing that)

[XVincentX]

// @kevinswiber @DrMegavolt What's your idea around the standing points?

[DrMegavolt]

what is wrong with just running migrate ? why do we need eg cli integration ?

[XVincentX]

I thought it was a requirement in order to give to the user an uniform interface to use the gateway.
Anyway, npx migrate or execute the bin file directly will do the job perfectly and it'll also save me some work. I'm fine removing this 👍

[codecov]

Codecov Report

Merging #494 into master will increase coverage by 0.01%.
The diff coverage is 94.33%.

@@            Coverage Diff             @@
##           master     #494      +/-   ##
==========================================
+ Coverage      92%   92.01%   +0.01%     
==========================================
  Files         219      221       +2     
  Lines        9280     9333      +53     
==========================================
+ Hits         8538     8588      +50     
- Misses        742      745       +3

Impacted Files	Coverage Δ
...9389756098-credential-username-userid-transform.js	91.3% <91.3%> (ø)
...migrations/credential-username-userid-transform.js	96.66% <96.66%> (ø)

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update 097fb93...750a419. Read the comment docs.

[XVincentX]

I removed the CLI integration and we'll stick with the default storing mechanism! 👍

[DrMegavolt]

LGTM

[XVincentX]

@DrMegavolt Please review this one ore time. I've modified the code to use the dao instead of the service — this is to skip the password hashing and have a simple password copy. In this way our users won't have to communicate any new password.

Also, I've added a test that should check the whole flow.

[DrMegavolt]

I guess the name should be
I insert some credentials by username

[XVincentX]

Yeah!

[DrMegavolt]

LGTM, let's merge