add more features support.
- id_token verification
- discovery.
add test case.
bump up version.
add fixture files.
add test cases. when raise exception.
add test cases. when raise timeout/socket_error.
add test cases. when raise timeout/socket_error.
Merge remote-tracking branch 'origin/support-id-token-verify' into support-id-token-verify

Conflicts:
	test/lib/omniauth/strategies/openid_connect_test.rb
WIP Fixing tests

Merge branch 'support-id-token-verify' of github.com:hiyosi/omniauth-openid-connect into hiyosi-support-id-token-verify

Conflicts:
  lib/omniauth/strategies/openid_connect.rb
  test/lib/omniauth/strategies/openid_connect_test.rb
go back to num of whitespace.
fix EOF line.
bump up version.
Merge remote-tracking branch 'remotes/upstream/hiyosi-support-id-token-verify' into support-id-token-verify
fix error testcase.

OmniAuth::Strategies::OpenIDConnectTest#test_state:
OpenSSL::SSL::SSLError: hostname "example.com" does not match the server certificate
fix error testcase.
OmniAuth::Strategies::OpenIDConnectTest#test_state

Maybe duplicate test case
   - test_state
   - test_callback_phase_with_invalid_state
update Gemfile.lock
fix error testcase.

OmniAuth::Strategies::OpenIDConnectTest#test_option_send_nonce
Merge remote-tracking branch 'origin/support-id-token-verify' into support-id-token-verify
fix error testcase.
OmniAuth::Strategies::OpenIDConnectTest#test_option_client_auth_method:
OpenIDConnect::Exception: Unexpected Token Type:
Merge remote-tracking branch 'origin/support-id-token-verify' into support-id-token-verify