Bump irb from 1.14.3 to 1.15.1

Bumps [irb](https://github.com/ruby/irb) from 1.14.3 to 1.15.1.
- [Release notes](https://github.com/ruby/irb/releases)
- [Commits](https://github.com/ruby/irb/compare/v1.14.3...v1.15.1)

---
updated-dependencies:
- dependency-name: irb
  dependency-type: direct:development
  update-type: version-update:semver-minor
...

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

Gemfile

@@ -66,7 +66,7 @@ group :test do
     gem 'rdoc', '~> 6.11'
     gem 'browserstack-local', '~> 1.4'
 
-    gem 'irb', '~> 1.14'
+    gem 'irb', '~> 1.15'
     gem 'pry-byebug', '~> 3.10', '>= 3.10.1'
 
     gem 'rest-client', '~> 2.1.0'

Gemfile.lock

@@ -82,7 +82,8 @@ GEM
       concurrent-ruby (~> 1.0)
     io-console (0.8.0)
     io-like (0.3.1)
-    irb (1.14.3)
+    irb (1.15.1)
+      pp (>= 0.6.0)
       rdoc (>= 4.0.0)
       reline (>= 0.4.2)
     json (2.9.1)
@@ -119,13 +120,16 @@ GEM
       ast (~> 2.4.1)
       racc
     power_assert (2.0.5)
+    pp (0.6.2)
+      prettyprint
+    prettyprint (0.2.0)
     pry (0.14.2)
       coderay (~> 1.1)
       method_source (~> 1.0)
     pry-byebug (3.10.1)
       byebug (~> 11.0)
       pry (>= 0.13, < 0.15)
-    psych (5.2.2)
+    psych (5.2.3)
       date
       stringio
     public_suffix (6.0.1)
@@ -264,7 +268,7 @@ DEPENDENCIES
   eventmachine (~> 1.2, >= 1.2.7)
   execjs (~> 2.10)
   geckodriver-helper (~> 0.24.0)
-  irb (~> 1.14)
+  irb (~> 1.15)
   json
   maxmind-db (~> 1.2)
   mime-types (~> 3.6)