Bump sinatra from 2.0.4 to 2.2.0

Bumps [sinatra](https://github.com/sinatra/sinatra) from 2.0.4 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@v2.0.4...v2.2.0)

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

Signed-off-by: dependabot[bot] <[email protected]>

Gemfile

@@ -1,7 +1,7 @@
 source 'https://rubygems.org'
 ruby "2.6.10"
 
-gem 'sinatra', '~> 2.0.1'
+gem 'sinatra', '~> 2.2.0'
 gem 'openactive', :git => "https://github.com/openactive/openactive.rb.git", :branch => "master"
 gem 'redis', '~> 3.3', '>= 3.3.1'
 gem 'local-geocoder'

Gemfile.lock

@@ -40,14 +40,15 @@ GEM
       mime-types-data (~> 3.2015)
     mime-types-data (3.2018.0812)
     multi_xml (0.6.0)
-    mustermann (1.0.3)
+    mustermann (1.1.2)
+      ruby2_keywords (~> 0.0.1)
     netrc (0.11.0)
     pry (0.12.2)
       coderay (~> 1.1.0)
       method_source (~> 0.9.0)
     public_suffix (3.0.3)
-    rack (2.0.6)
-    rack-protection (2.0.4)
+    rack (2.2.4)
+    rack-protection (2.2.0)
       rack
     rack-test (0.6.3)
       rack (>= 1.0)
@@ -71,21 +72,22 @@ GEM
       diff-lcs (>= 1.2.0, < 2.0)
       rspec-support (~> 3.8.0)
     rspec-support (3.8.0)
+    ruby2_keywords (0.0.5)
     safe_yaml (1.0.4)
     simplecov (0.16.1)
       docile (~> 1.1)
       json (>= 1.8, < 3)
       simplecov-html (~> 0.10.0)
     simplecov-html (0.10.2)
-    sinatra (2.0.4)
+    sinatra (2.2.0)
       mustermann (~> 1.0)
-      rack (~> 2.0)
-      rack-protection (= 2.0.4)
+      rack (~> 2.2)
+      rack-protection (= 2.2.0)
       tilt (~> 2.0)
     term-ansicolor (1.7.0)
       tins (~> 1.0)
     thor (0.19.4)
-    tilt (2.0.8)
+    tilt (2.0.11)
     tins (1.20.2)
     trollop (2.9.9)
     unf (0.1.4)
@@ -109,7 +111,7 @@ DEPENDENCIES
   redis (~> 3.3, >= 3.3.1)
   redis-namespace
   rspec (~> 3.6)
-  sinatra (~> 2.0.1)
+  sinatra (~> 2.2.0)
   webmock (~> 2.1)
 
 RUBY VERSION