Bump rdoc from 3.12.1 to 6.1.2.1

Bumps [rdoc](https://github.com/ruby/rdoc) from 3.12.1 to 6.1.2.1.
- [Release notes](https://github.com/ruby/rdoc/releases)
- [Changelog](https://github.com/ruby/rdoc/blob/master/History.rdoc)
- [Commits](ruby/rdoc@v3.12.1...v6.1.2.1)

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

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

Author: dependabot[bot]

Gemfile

@@ -4,7 +4,7 @@ gemspec
 
 group :developement do
   gem 'rake', '>= 0.9'
-  gem 'rdoc', '3.12.1'
+  gem 'rdoc', '6.1.2.1'
 end
 
 group :development, :test do

Gemfile.lock

@@ -45,7 +45,7 @@ GEM
     forgery (0.5.0)
     gherkin (2.9.3)
       json (>= 1.4.6)
-    json (1.8.6)
+    json (2.6.3)
     libwebsocket (0.1.3)
       addressable
     mime-types (1.18)
@@ -57,8 +57,7 @@ GEM
     rack-test (0.6.1)
       rack (>= 1.0)
     rake (0.9.2.2)
-    rdoc (3.12.1)
-      json (~> 1.4)
+    rdoc (6.1.2.1)
     rexml (3.2.5)
     rspec (2.10.0)
       rspec-core (~> 2.10.0)
@@ -90,7 +89,7 @@ DEPENDENCIES
   cucumber-rails
   forgery
   rake (>= 0.9)
-  rdoc (= 3.12.1)
+  rdoc (= 6.1.2.1)
   rspec (~> 2.10)
 
 BUNDLED WITH