Remove multi_json dependency

Author: sferik

lib/omniauth/strategies/oauth2.rb

@@ -4,7 +4,6 @@
 require 'socket'       # for SocketError
 require 'timeout'      # for Timeout::Error
 require 'faraday'      # for Faraday::Error::TimeoutError and Faraday::Error::ConnectionFailed
-require 'multi_json'   # for MultiJson::DecodeError
 
 module OmniAuth
   module Strategies
@@ -78,8 +77,6 @@ def callback_phase # rubocop:disable AbcSize, CyclomaticComplexity, MethodLength
         end
       rescue ::OAuth2::Error, CallbackError => e
         fail!(:invalid_credentials, e)
-      rescue ::MultiJson::DecodeError => e
-        fail!(:invalid_response, e)
       rescue ::Timeout::Error, ::Errno::ETIMEDOUT, Faraday::Error::TimeoutError => e
         fail!(:timeout, e)
       rescue ::SocketError, Faraday::Error::ConnectionFailed => e

omniauth-oauth2.gemspec

@@ -4,7 +4,6 @@ require 'omniauth-oauth2/version'
 
 Gem::Specification.new do |gem|
   gem.add_dependency 'faraday',   ['>= 0.8', '< 0.10']
-  gem.add_dependency 'multi_json', '~> 1.3'
   gem.add_dependency 'oauth2',     '~> 1.0'
   gem.add_dependency 'omniauth',   '~> 1.2'