Bump rack from 2.0.7 to 2.0.8

Bumps [rack](https://github.com/rack/rack) from 2.0.7 to 2.0.8.
- [Release notes](https://github.com/rack/rack/releases)
- [Changelog](https://github.com/rack/rack/blob/master/CHANGELOG.md)
- [Commits](rack/rack@2.0.7...2.0.8)

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

Author: dependabot[bot]

Gemfile.lock

@@ -17,9 +17,11 @@ GEM
       http_parser.rb (~> 0.6.0)
     ethon (0.12.0)
       ffi (>= 1.3.0)
+    eventmachine (1.2.7)
     eventmachine (1.2.7-x64-mingw32)
     faraday (0.15.4)
       multipart-post (>= 1.2, < 3)
+    ffi (1.11.1)
     ffi (1.11.1-x64-mingw32)
     forwardable-extended (2.6.0)
     html-proofer (3.11.0)
@@ -85,6 +87,8 @@ GEM
     minitest (5.11.3)
     multipart-post (2.1.1)
     netrc (0.11.0)
+    nokogiri (1.10.3)
+      mini_portile2 (~> 2.4.0)
     nokogiri (1.10.3-x64-mingw32)
       mini_portile2 (~> 2.4.0)
     octokit (4.14.0)
@@ -95,7 +99,7 @@ GEM
     pathutil (0.16.2)
       forwardable-extended (~> 2.6)
     public_suffix (3.1.0)
-    rack (2.0.7)
+    rack (2.0.8)
     rainbow (3.0.0)
     rb-fsevent (0.10.3)
     rb-inotify (0.10.0)
@@ -131,10 +135,10 @@ GEM
     w3c_validators (1.3.4)
       json (>= 1.8)
       nokogiri (~> 1.6)
-    wdm (0.1.1)
     yell (2.2.0)
 
 PLATFORMS
+  ruby
   x64-mingw32
 
 DEPENDENCIES
@@ -155,7 +159,6 @@ DEPENDENCIES
   rubocop (~> 0.50)
   rubocop-rails
   w3c_validators (~> 1.3)
-  wdm (>= 0.1.0)
 
 BUNDLED WITH
    1.16.2