add timeout option

[naoa]

We would like to set timeout for Faraday.

[gbaptista]

Hi @naoa, thank you for your contribution!

I took the liberty to slightly change your implementation to the following:

Gemini.new(
  credentials: { service: 'vertex-ai-api', region: 'us-east4' },
  options: {
    model: 'gemini-pro',
    connection: { request: { timeout: 5 } }
  }
)

The changes have been made to allow for more precise timeout configurations and also to pave the way for additional options related to Faraday in the future:

Gemini.new(
  credentials: { service: 'vertex-ai-api', region: 'us-east4' },
  options: {
    model: 'gemini-pro',
    connection: {
      request: {
        timeout: 5,
        open_timeout: 5,
        read_timeout: 5,
        write_timeout: 5
      }
    }
  }
)

Hope that's okay; feel free to open another PR if you prefer to change something.

[gbaptista]

Merged and released; the new version is now available on RubyGems:

gem 'gemini-ai', '~> 3.1'

[naoa]

Thanks for your quick action!