Bump rack from 2.0.8 to 2.2.3 (#7)

Bumps [rack](https://github.com/rack/rack) from 2.0.8 to 2.2.3.
- [Release notes](https://github.com/rack/rack/releases)
- [Changelog](https://github.com/rack/rack/blob/master/CHANGELOG.md)
- [Commits](rack/rack@2.0.8...2.2.3)

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

Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Gemfile.lock

@@ -8,6 +8,7 @@ PATH
 GEM
   remote: https://rubygems.org/
   specs:
+    diff-lcs (1.4.2)
     faraday (0.15.4)
       multipart-post (>= 1.2, < 3)
     hashie (3.6.0)
@@ -27,13 +28,30 @@ GEM
     omniauth-oauth2 (1.6.0)
       oauth2 (~> 1.1)
       omniauth (~> 1.9)
-    rack (2.0.8)
+    rack (2.2.3)
+    rake (10.5.0)
+    rspec (3.9.0)
+      rspec-core (~> 3.9.0)
+      rspec-expectations (~> 3.9.0)
+      rspec-mocks (~> 3.9.0)
+    rspec-core (3.9.2)
+      rspec-support (~> 3.9.3)
+    rspec-expectations (3.9.2)
+      diff-lcs (>= 1.2.0, < 2.0)
+      rspec-support (~> 3.9.0)
+    rspec-mocks (3.9.1)
+      diff-lcs (>= 1.2.0, < 2.0)
+      rspec-support (~> 3.9.0)
+    rspec-support (3.9.3)
 
 PLATFORMS
   ruby
 
 DEPENDENCIES
+  bundler (~> 1.11)
   omniauth-bn-office365!
+  rake (~> 10.0)
+  rspec (~> 3.0)
 
 BUNDLED WITH
    1.16.2