[Rails5] Ruby on Rails stub server requires MySQL but does not use it

[ledsun]

Description

The Ruby on Rails stub server requires MySQL.
Its Gemfile includes line blew:

# Use mysql as the database for Active Record
gem 'mysql2', '>= 0.3.18', '< 0.5'

To start the Ruby on Rails stub server, we need to install MySQL in the development environment.
However, the Ruby on Rails stub server does not use the database.
I think this is a meaningless cost.

openapi-generator version

3.0.0

OpenAPI declaration file content or url

Any.

Command line used for generation

bin/rails5-petstore-server.sh

Steps to reproduce

bin/rails5-petstore-server.sh

Related issues/PRs

No.

Suggest a fix/enhancement

Switch the database to SQLite for Ruby on Rails stub server like:
https://github.com/ledsun/openapi-generator/tree/rails_reduce_dependency

We can start the Ruby on Rails stub server in fewer steps.

[wing328]

@ledsun thanks for reporting the issue. I agree with you SQLite works better for new users who use the auto-generated Ruby-on-Rails app for the first time.

May I know if you've time to contribute a PR with the enhancement?

[ledsun]

I can create a PR today or tomorrow.

[ackintosh]

Changed to '3.1.0' as #279 is planed to release in v3.1.0.

[ackintosh]

@ledsun The enhancement is merged into 3.1.0 branch. ✨ can we close this issue?

[wing328]

Sure.