Update to Phoenix v1.6

[nelsonic]

Given the recent Phoenix v1.6.0-rc.1 see: dwyl/learn-phoenix-framework#143

Todo

• Go through this tutorial again and update to the latest Phoenix
  • Confirm if there is any added complexity or if v1.6 simplifies things.
• Create Pull Request with changes
• Assign PR for review

I expect this exercise to take around T2h because the tutorial is quite long and we need to test all the steps.
It might take less time, but this is the estimate. 💭

[nelsonic]

Read through the upgrade guide: https://gist.github.com/chrismccord/2ab350f154235ad4a4d0f4de6decba7b
Looks fairly straightforward.
I'm still holding off doing it until more edge cases are ironed out so I don't have to waste too much time.

[nelsonic]

We've now updated quite a few of our Apps to Phoenix `1.6 without any issues: 🚀

• auth: update deps #146 auth#147
• auth_plug_example: Update to phoenix 1.6 issue #11 auth_plug_example#13
• elixir-auth-google-demo Update to Phoenix 1.6 and Elixir 1.12.3 fixes #6 elixir-auth-google-demo#7

Fairly certain we could tackle this issue/update now. 💭
@ajmeese7 if you're keen to dive in - very much appreciated - let us know how you get on.
(You should have write-access, please create a PR. Thanks!)

[ajmeese7]

@nelsonic I'll get started on that now :)

[nelsonic]

Thanks again @ajmeese7 🙌

[nelsonic]

Testing on my localhost there are still a few things to tidy up for the 1.5.x to 1.6.x migration.
I'm following this guide: https://gist.github.com/chrismccord/2ab350f154235ad4a4d0f4de6decba7b ⏳

[nelsonic]

Working on localhost:

[nelsonic]

Suuuuuuuuper annoyingly, Travis-CI has decided to cap the number of "Credits" that Open Source projects get:

So my PR #62 is not running CI ... 🤦‍♂️ See: dwyl/learn-travis#67

But here's a screenshot of the tests passing on localhost:

[nelsonic]

Replaced Travis-CI with GitHub Actions: #63 ✅