Support OmniAuth 2.0 series

[koshilife]

OmniAuth 2.0 was released includes to resolved a CSRF vulnerability and some behaviors changed.

See below the release note for details.
https://github.com/omniauth/omniauth/releases/tag/v2.0.0

If an OmniAuth Strategy has overridden callback_url, it is needed to follow changes because of the callback_path changes.

I think this library is also the target.
https://github.com/kazasiki/omniauth-line/blob/master/lib/omniauth/strategies/line.rb#L24

In case of using OmniAuth 2.0 and script_name, the redirect url now includes the script_name twice so it might occur redirect url mismatch error.

I suggest this library should release 2 versions for correspond to OmniAuth 1.x and 2.0 series.

• Release 0.1.1 bumped micro version as support for OmniAuth 1.x.
• Release 1.0.0 bumped major version as support for OmniAuth 2.0 series.

I’m going to make pull requests.

[koshilife]

Hi, @kazasiki

I opened two PRs (#33 #34)
Could you review theses?

[koshilife]

Hi, @kazasiki

For your information I summarized and translated in Japanese the guide of Upgrading to OmniAuth 2.0.

https://zenn.dev/koshilife/articles/b71f8cfcb50e33

I hope it helps you to understand these PRs.