Support for Elixir 1.17

[josecfreittas]

Elixir 1.17 brings a new format for the coverage output. This was causing parsing errors, and this PR fixes this.

Closes #30

[github-actions]

Tests summary

Finished in 0.1 seconds (0.07s async, 0.03s sync)
Randomized with seed 991481

✅ 0 failures (1 doctest, 38 tests)
✅ 100% coverage (90% is the minimum)

Coverage details

Percentage | Module
-----------|--------------------------
   100.00% | Example.Application
   100.00% | Example.Lists
   100.00% | Example.Math
   100.00% | Example.Strings
   100.00% | ExampleWeb
   100.00% | ExampleWeb.ConnCase
   100.00% | ExampleWeb.Endpoint
   100.00% | ExampleWeb.ErrorJSON
   100.00% | ExampleWeb.IndexController
   100.00% | ExampleWeb.Router
-----------|--------------------------
   100.00% | Total