Bump sinatra from 1.4.7 to 2.2.0

Bumps [sinatra](https://github.com/sinatra/sinatra) from 1.4.7 to 2.2.0.
- [Release notes](https://github.com/sinatra/sinatra/releases)
- [Changelog](https://github.com/sinatra/sinatra/blob/master/CHANGELOG.md)
- [Commits](https://github.com/sinatra/sinatra/compare/v1.4.7...v2.2.0)

---
updated-dependencies:
- dependency-name: sinatra
  dependency-type: direct:development
...

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

Gemfile.lock

@@ -28,8 +28,10 @@ GEM
       tilt
     i18n (0.7.0)
     minitest (5.9.1)
-    rack (1.6.5)
-    rack-protection (1.5.3)
+    mustermann (1.1.1)
+      ruby2_keywords (~> 0.0.1)
+    rack (2.2.3)
+    rack-protection (2.2.0)
       rack
     rack-test (0.6.3)
       rack (>= 1.0)
@@ -47,13 +49,15 @@ GEM
       diff-lcs (>= 1.2.0, < 2.0)
       rspec-support (~> 3.5.0)
     rspec-support (3.5.0)
-    sinatra (1.4.7)
-      rack (~> 1.5)
-      rack-protection (~> 1.4)
-      tilt (>= 1.3, < 3)
+    ruby2_keywords (0.0.5)
+    sinatra (2.2.0)
+      mustermann (~> 1.0)
+      rack (~> 2.2)
+      rack-protection (= 2.2.0)
+      tilt (~> 2.0)
     sqlite3 (1.3.12)
     thread_safe (0.3.5)
-    tilt (2.0.5)
+    tilt (2.0.10)
     timecop (0.8.1)
     tzinfo (1.2.2)
       thread_safe (~> 0.1)