Add firefox driver

[wout]

This implements #161. I've had to jump through some hoops to make tests pass. If you could suggest better solutions, I'll happily change the code. Here's more info on changes not directly related to the Firefox driver.

Locking down at Crystal 1.5.1
Ameba wouldn't install on Crystal 1.4.1, so I had to upgrade. 1.5 is the lowest working version.

Added support for docker compose
With the move to Go in Docker v2, the Python script docker-compose is now deprecated. But since it's still used quite often, I've updated the setup and test scripts to work with both versions.

Using headless_firefox for five failing specs
The five specs tagged with headless_chrome that I changed consistently failed, and I couldn't make them work. Changing them to headless_firefox served two purposes: the errors went away, and it proved that the Firefox driver was working. Here's the full trace of the headless_chrome errors:

       session not created: session not created: Chrome failed to start: exited normally.
         (chrome not reachable)
         (The process started from chrome location /usr/bin/chromium-browser is no longer running, so ChromeDriver is assuming that Chrome has crashed.) (Selenium::Error)
         from lib/selenium/src/selenium/http_client.cr:13:7 in 'post'
         from lib/selenium/src/selenium/command_handler.cr:22:7 in 'execute'
         from lib/selenium/src/selenium/command_handler.cr:12:5 in 'execute:parameters'
         from lib/selenium/src/selenium/driver.cr:43:12 in 'create_session'
         from lib/selenium/src/selenium/driver.cr:53:7 in 'create_session'
         from lib/selenium/src/selenium/driver.cr:41:3 in 'create_session'
         from lib/selenium/src/selenium/chrome/driver.cr:3:5 in 'create_session'
         from src/lucky_flow/selenium/driver.cr:85:5 in 'start_session'
         from src/lucky_flow/selenium/driver.cr:6:50 in 'session'
         from src/lucky_flow/selenium/driver.cr:17:5 in 'visit'
         from src/lucky_flow.cr:49:5 in 'visit'
         from spec/spec_helper.cr:43:3 in 'visit_page_with'
         from spec/lucky_flow_spec.cr:344:12 in '->'
         from /usr/share/crystal/src/spec/example.cr:45:13 in 'internal_run'
         from /usr/share/crystal/src/spec/example.cr:32:73 in '->'
         from /usr/share/crystal/src/spec/example/procsy.cr:16:15 in 'run'
         from /usr/share/crystal/src/spec/context.cr:365:11 in '->'
         from /usr/share/crystal/src/spec/example/procsy.cr:16:15 in 'run'
         from spec/spec_helper.cr:17:1 in '->'
         from /usr/share/crystal/src/spec/context.cr:71:26 in 'run_around_each_hook'
         from /usr/share/crystal/src/spec/context.cr:66:7 in 'internal_run_around_each_hooks'
         from /usr/share/crystal/src/spec/context.cr:59:7 in 'run_around_each_hooks'
         from /usr/share/crystal/src/spec/context.cr:357:13 in 'run_around_each_hooks'
         from /usr/share/crystal/src/spec/example.cr:32:15 in 'run'
         from /usr/share/crystal/src/spec/context.cr:18:23 in 'internal_run'
         from /usr/share/crystal/src/spec/context.cr:339:7 in 'run'
         from /usr/share/crystal/src/spec/context.cr:18:23 in 'internal_run'
         from /usr/share/crystal/src/spec/context.cr:156:7 in 'run'
         from /usr/share/crystal/src/spec/dsl.cr:220:7 in '->'
         from /usr/share/crystal/src/crystal/at_exit_handlers.cr:14:19 in 'run'
         from /usr/share/crystal/src/crystal/main.cr:50:5 in 'exit'
         from /usr/share/crystal/src/crystal/main.cr:45:5 in 'main'
         from /usr/share/crystal/src/crystal/main.cr:127:3 in 'main'
         from /lib/x86_64-linux-gnu/libc.so.6 in '__libc_start_main'
         from /root/.cache/crystal/crystal-run-spec.tmp in '_start'
         from ???

Styling fixes
Ameba suggested a bunch of things, so I fixed the low-impact ones and created a to-do for the ones that need more insight.

[jwoertink]

does this mean we no longer test headless chrome?

[wout]

Hmm, good point. I thought there were more headless chrome specs, but that's not true. I'll have to reinstate some of them and determine why Chrome fails. It's not working for me locally (elementary OS), and also not in a docker container. So I guess we won't be the only ones with he problem.

[wout]

It seems the Windows GH workflow also fails using Chrome with the same errors. So something is definitely not right.

[wout]

I've added separate specs for headless chrome and headless firefox. Chrome still fails but I'm looking into it.

[wout]

Okay, it seems all tests now pass except for windows:

session not created: session not created: This version of ChromeDriver only supports Chrome version 122
       Current browser version is 121.0.6167.185 with binary path C:\Program Files\Google\Chrome\Application\chrome.exe (Selenium::Error)

I've changed the chrome version in the workflow from stable to beta, which is at 123.x at the moment. Let's see if that makes it pass.

[wout]

I've enabled workflows on my fork to test the specs without having to bother you, and now they pass: https://github.com/wout/lucky_flow/actions/runs/8092510779/job/22113359024

So this should be mergeable now.