Remove dependency on MultiJSON

Gemfile.lock

@@ -1,9 +1,10 @@
 PATH
   remote: .
   specs:
-    omniauth-keycloak (1.4.1)
+    omniauth-keycloak (1.4.2)
+      faraday
       json-jwt (~> 1.13.0)
-      omniauth (~> 2.0.4)
+      omniauth (>= 2.0)
       omniauth-oauth2 (~> 1.7.1)
 
 GEM

lib/keycloak/version.rb

@@ -1,5 +1,5 @@
 module Omniauth
   module Keycloak
-    VERSION = "1.4.2"
+    VERSION = "1.4.3"
   end
 end

lib/omniauth/strategies/keycloak-openid.rb

@@ -31,7 +31,7 @@ module OmniAuth
                     log :debug, "Going to get Keycloak configuration. URL: #{config_url}"
                     response = Faraday.get config_url
                     if (response.status == 200)
-                        json = MultiJson.load(response.body)
+                        json = JSON.parse(response.body)
 
                         @certs_endpoint = json["jwks_uri"]
                         @userinfo_endpoint = json["userinfo_endpoint"]
@@ -47,7 +47,7 @@ module OmniAuth
                         log :debug, "Going to get certificates. URL: #{@certs_endpoint}"
                         certs = Faraday.get @certs_endpoint
                         if (certs.status == 200)
-                            json = MultiJson.load(certs.body)
+                            json = JSON.parse(response.body)
                             @certs = json["keys"]
                             log :debug, "Successfully got certificate. Certificate length: #{@certs.length}"
                         else

omniauth-keycloak.gemspec

@@ -26,6 +26,7 @@ Gem::Specification.new do |spec|
   spec.add_dependency "omniauth", ">= 2.0"
   spec.add_dependency "omniauth-oauth2", "~> 1.7.1"
   spec.add_dependency "json-jwt", "~> 1.13.0"
+  spec.add_dependency "faraday"
 
   spec.add_development_dependency "bundler", "~> 2.2"
   spec.add_development_dependency "rake", "~> 13.0"