Rubyバージョンとgemのアップデート

[JunichiIto]

omniauth/omniauth-github#89 の警告を消すためです。

Hello there!

On April 11th, 2020 at 23:26 (UTC) your application (Rubyist Connect Development) used an access token (with the User-Agent Faraday v0.17.0) as part of a query parameter to access an endpoint through the GitHub API.

https://api.github.com/user

Please use the Authorization HTTP header instead as using the `access_token` query parameter is deprecated.

Depending on your API usage, we'll be sending you this email reminder on a monthly basis.

Visit https://developer.github.com/changes/2020-02-10-deprecating-auth-through-query-param for more information about suggested workarounds and removal dates.

Thanks,
The GitHub Team

[JunichiIto]

本番リリース済みです。