support OAuth authentication

[koshilife]

We support OAuth authentication by new OAuthAPI class.

Since OAuth authentication is provided by kintone platform, it's worth to provide a method from the library.

OAuthAPI class usage is following and we updated README also.

# Use OAuth authentication
api = Kintone::OAuthApi.new("example.cybozu.com", "access_token")
# if set oauth options below, you can refresh the access_token.
oauth_options = {
  client_id: 'client_id',
  client_secret: 'client_secret',
  refresh_token: 'refresh_token',
  expires_at: 1599921045
}
api = Kintone::OAuthApi.new("example.cybozu.com", "access_token", oauth_options)
# get new token.
api.refresh!
api.access_token.token
# => "new_access_token"

[koshilife]

We made a gem kintone-oauth-extension in temporary for someone want to use oauth authentication.

You can try this feature.

gem install kintone-oauth-extension

or execute bundle install command after you insert the following into Gemfile

gem 'kintone-oauth-extension'