Bump json

Gemfile

@@ -21,7 +21,7 @@ gem "diaspora_federation-rails", "0.2.5"
 # API and JSON
 
 gem "acts_as_api", "1.0.1"
-gem "json",        "2.1.0"
+gem "json",        "2.2.0"
 gem "json-schema", "2.8.1"
 
 # Authentication

Gemfile.lock

@@ -340,7 +340,7 @@ GEM
     js_image_paths (0.1.1)
       rails (>= 4.0, < 6.0)
       sprockets (>= 3.0.0)
-    json (2.1.0)
+    json (2.2.0)
     json-jwt (1.9.4)
       activesupport
       aes_key_wrap
@@ -812,7 +812,7 @@ DEPENDENCIES
   jquery-rails (= 4.3.3)
   js-routes (= 1.4.4)
   js_image_paths (= 0.1.1)
-  json (= 2.1.0)
+  json (= 2.2.0)
   json-schema (= 2.8.1)
   json-schema-rspec (= 0.0.4)
   leaflet-rails (= 1.3.1)