Update ruby-prof requirement from 0.13.0 to 0.18.0

Updates the requirements on [ruby-prof](https://github.com/ruby-prof/ruby-prof) to permit the latest version.
- [Changelog](https://github.com/ruby-prof/ruby-prof/blob/master/CHANGES)
- [Commits](ruby-prof/ruby-prof@v0.13.0...0.18.0)

---
updated-dependencies:
- dependency-name: ruby-prof
  dependency-type: direct:development
...

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

Gemfile

@@ -27,7 +27,7 @@ group :development, :test do
   gem "rubocop-rspec", "2.29.1", require: false
 
   # Performance profiler
-  gem "ruby-prof", "0.13.0", require: false
+  gem "ruby-prof", "0.18.0", require: false
   gem "ruby-prof-flamegraph", "0.3.0", require: false
 
   # Type checker