Merge pull request #42 from splitrb/dependabot/bundler/sinatra-2.0.4

[Security] Bump sinatra from 2.0.1 to 2.0.4

Author: andrew

Gemfile.lock

@@ -1,16 +1,16 @@
 GEM
   remote: http://rubygems.org/
   specs:
-    mustermann (1.0.2)
-    rack (2.0.4)
-    rack-protection (2.0.1)
+    mustermann (1.0.3)
+    rack (2.0.6)
+    rack-protection (2.0.4)
       rack
     redis (4.0.1)
     simple-random (1.0.3)
-    sinatra (2.0.1)
+    sinatra (2.0.4)
       mustermann (~> 1.0)
       rack (~> 2.0)
-      rack-protection (= 2.0.1)
+      rack-protection (= 2.0.4)
       tilt (~> 2.0)
     split (3.2.0)
       redis (>= 2.1)