Ease debugging, fix some CI issues, tweak folder structure (#200)

* Enable debug for OTP versions' listings

* Make it easier to detect

* Prevent error annotation on expected error

The fact that one mirror fails in the above test and others follow
working is test enough for me

A single failing mirror should fail, but it's confusing to have
an error annotation for a success (via continue-on-error) while
not being able to suppress it via GitHub Actions

* Trying to figure out why we have a rebar_core exception

Might simply be that the bug is already fixed and we need to bump rebar3

* Try to debug into non-JSON input

* Prevent error in rebar_core

We're getting Access Denied for
Fetching registry from "https://repo.hex.pm:443/registry.ets.gz?"

* Try to figure out what's breaking tests

* Make jsonParse(...).map failure more understandable

* Ease test maintenance

* Tweak folder structure while moving console._ to core._

test/projects/elixir_mix/README.md

@@ -0,0 +1,21 @@
+# Test
+
+**TODO: Add description**
+
+## Installation
+
+If [available in Hex](https://hex.pm/docs/publish), the package can be installed
+by adding `test` to your list of dependencies in `mix.exs`:
+
+```elixir
+def deps do
+  [
+    {:test, "~> 0.1.0"}
+  ]
+end
+```
+
+Documentation can be generated with [ExDoc](https://github.com/elixir-lang/ex_doc)
+and published on [HexDocs](https://hexdocs.pm). Once published, the docs can
+be found at [https://hexdocs.pm/test](https://hexdocs.pm/test).
+