Add gem version and SemVer compatibility badges to README (#473)

README.md

@@ -1,13 +1,16 @@
 # Bugsnag exception reporter for Ruby
 [![build status](https://travis-ci.org/bugsnag/bugsnag-ruby.svg?branch=master)](https://travis-ci.org/bugsnag/bugsnag-ruby)
+![Gem Version](https://badge.fury.io/rb/bugsnag.svg)
+[![SemVer](https://api.dependabot.com/badges/compatibility_score?dependency-name=bugsnag&package-manager=bundler&version-scheme=semver)](https://dependabot.com/compatibility-score.html?dependency-name=bugsnag&package-manager=bundler&version-scheme=semver)
+
 
 
 The Bugsnag exception reporter for Ruby gives you instant notification of exceptions thrown from your **[Rails](https://www.bugsnag.com/platforms/rails)**, **Sinatra**, **Rack** or **plain Ruby** app. Any uncaught exceptions will trigger a notification to be sent to your Bugsnag project.
 
 ## Features
 
 * Automatically report unhandled exceptions and crashes
-* Report handled exceptions 
+* Report handled exceptions
 * Attach user information to determine how many people are affected by a crash
 * Send customized diagnostic data