Update pry-stack_explorer requirement from ~> 0.4.11 to ~> 0.5.1

Updates the requirements on [pry-stack_explorer](https://github.com/pry/pry-stack_explorer) to permit the latest version.
- [Release notes](https://github.com/pry/pry-stack_explorer/releases)
- [Changelog](https://github.com/pry/pry-stack_explorer/blob/master/CHANGELOG)
- [Commits](pry/pry-stack_explorer@v0.4.11...v0.5.1)

---
updated-dependencies:
- dependency-name: pry-stack_explorer
  dependency-type: direct:development
...

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

nose.gemspec

@@ -41,7 +41,7 @@ Gem::Specification.new do |s|
   s.add_development_dependency 'memory_profiler', '~> 1.0.0'
   s.add_development_dependency 'pry-byebug', '~> 3.9.0'
   s.add_development_dependency 'pry-doc', '~> 1.1.0'
-  s.add_development_dependency 'pry-stack_explorer', '~> 0.4.11'
+  s.add_development_dependency 'pry-stack_explorer', '~> 0.5.1'
   s.add_development_dependency 'ronn', '~> 0.7.3'
   s.add_development_dependency 'rspec', '~> 3.10.0'
   s.add_development_dependency 'rspec-core', '~> 3.10.0'