Bump json from 2.2.0 to 2.3.1

Bumps [json](https://github.com/flori/json) from 2.2.0 to 2.3.1.
- [Release notes](https://github.com/flori/json/releases)
- [Changelog](https://github.com/flori/json/blob/master/CHANGES.md)
- [Commits](https://github.com/flori/json/compare/v2.2.0...v2.3.1)

Signed-off-by: dependabot[bot] <support@github.com>

Gemfile.lock

@@ -161,7 +161,7 @@ GEM
     httpclient (2.8.3)
     i18n (0.9.5)
       concurrent-ruby (~> 1.0)
-    json (2.2.0)
+    json (2.3.1)
     jwt (2.2.1)
     kramdown (1.17.0)
     memoist (0.16.0)

README.md

@@ -1,5 +1,3 @@
-⚠️⚠️⚠️ This library has been deprecated and will be removed in the future. ⚠️⚠️⚠️
-
 # PlayerKit
 
 [![CI Status](http://img.shields.io/travis/ghking/PlayerKit.svg?style=flat)](https://travis-ci.org/vimeo/PlayerKit)