Old Ruby version installation with RVM

This will be a quick post on how to quickly install an old Ruby version on your Linux or Mac computer, with the help of RVM, the Ruby Version Manager:

First and foremost, if you haven’t already, let’s install RVM: For the current user (no system-wide installation), you have to:
```
 \curl -sSL https://get.rvm.io | bash -s stable --ruby
```
Once you have RVM installed, we’ll request the installation of an old Ruby version, with its quirks and things:
```
 $ rvm pkg install openssl
```
With that dependency installed, we’re now able to install the selected Ruby version with OpenSSL support:
```
 $ rvm install ruby-3.0.5 --with-openssl-dir=$HOME/.rvm/usr
```
It will take a while.
With the version installed, let’s install Bundler:
```
 $ rvm all do gem install bundler
```

Let’s use the newly installed Ruby version:

 $ rvm use ruby-3.0.5

 RVM is not a function, selecting rubies with 'rvm use ...' will not work.

 You need to change your terminal emulator preferences to allow login shell.
 Sometimes it is required to use `/bin/bash --login` as the command.
 Please visit https://rvm.io/integration/gnome-terminal/ for an example.

Oops! It looks we need to allow login shell for the macros to work:

 $ bash --login
 $ rvm use ruby-3.0.5
 Using /home/manuelmc/.rvm/gems/ruby-3.0.5