Upgrade to Elixir 1.14.0

Upgrade Elixir to 1.14.0
Upgrade Alpine to 3.16
Update Phoenix to 1.6.12

Change to a base image with Erlang and Elixir. Remove asdf.

Update to Elixir 1.13.4

Update to Erlang OTP 24.3
Update to Elixir 1.13.4
Update to Phoenix 1.6.6

Alpine 3.15 / WeasyPrint

• Replace WkHtmlToPdf with WeasyPrint
• Upgrade to Alpine 3.15

Update to Elixir 1.13.1

Upgrade elixir 1.13 (#2)

* WIP: Upgrade Elixir to 1.13

* Downgrade to Alpine 3.14. Remove SCTP support in Erlang

* Update to OTP 24.2 and Elixir 1.13.1

Elixir 1.12.2

Elixir: 1.12.2
Phoenix: 1.5.7
Nodejs: 14.16.0