Update fakefs requirement from ~> 1.0 to ~> 2.0 (#1929)

Updates the requirements on [fakefs](https://github.com/fakefs/fakefs) to permit the latest version.
- [Release notes](https://github.com/fakefs/fakefs/releases)
- [Changelog](https://github.com/fakefs/fakefs/blob/master/CHANGELOG.md)
- [Commits](fakefs/fakefs@v1.0.0...v2.0.0)

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

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Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

test-kitchen.gemspec

@@ -44,7 +44,7 @@ Gem::Specification.new do |gem|
   gem.add_development_dependency "aruba",     ">= 0.11", "< 3.0"
   gem.add_development_dependency "countloc",  "~> 0.4"
   gem.add_development_dependency "cucumber",  ">= 2.1", "< 8.0"
-  gem.add_development_dependency "fakefs",    "~> 1.0"
+  gem.add_development_dependency "fakefs",    "~> 2.0"
   gem.add_development_dependency "maruku",    "~> 0.6"
   gem.add_development_dependency "minitest",  "~> 5.3", "< 5.16"
   gem.add_development_dependency "mocha",     "~> 1.1"