Bump sinatra from 2.0.7 to 2.2.0

Bumps [sinatra](https://github.com/sinatra/sinatra) from 2.0.7 to 2.2.0.
- [Release notes](https://github.com/sinatra/sinatra/releases)
- [Changelog](https://github.com/sinatra/sinatra/blob/master/CHANGELOG.md)
- [Commits](sinatra/sinatra@v2.0.7...v2.2.0)

---
updated-dependencies:
- dependency-name: sinatra
  dependency-type: indirect
...

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

Author: dependabot[bot]

Gemfile.lock

@@ -82,7 +82,8 @@ GEM
     mini_mime (1.1.0)
     mini_portile2 (2.5.3)
     minitest (5.14.4)
-    mustermann (1.0.3)
+    mustermann (1.1.1)
+      ruby2_keywords (~> 0.0.1)
     nio4r (2.5.7)
     nokogiri (1.11.7)
       mini_portile2 (~> 2.5.0)
@@ -91,7 +92,7 @@ GEM
       racc (~> 1.4)
     racc (1.5.2)
     rack (2.2.3)
-    rack-protection (2.0.7)
+    rack-protection (2.2.0)
       rack
     rack-test (1.1.0)
       rack (>= 1.0, < 3)
@@ -126,11 +127,12 @@ GEM
     rb-inotify (0.10.1)
       ffi (~> 1.0)
     redis (4.1.3)
+    ruby2_keywords (0.0.5)
     simple-random (1.0.3)
-    sinatra (2.0.7)
+    sinatra (2.2.0)
       mustermann (~> 1.0)
-      rack (~> 2.0)
-      rack-protection (= 2.0.7)
+      rack (~> 2.2)
+      rack-protection (= 2.2.0)
       tilt (~> 2.0)
     split (3.4.1)
       redis (>= 2.1)