Update mocha requirement from ~> 2.1 to ~> 3.0

Updates the requirements on [mocha](https://github.com/freerange/mocha) to permit the latest version.
- [Changelog](https://github.com/freerange/mocha/blob/main/RELEASE.md)
- [Commits](freerange/mocha@v2.1.0...v3.0.0)

---
updated-dependencies:
- dependency-name: mocha
  dependency-version: 3.0.0
  dependency-type: direct:development
...

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

Author: dependabot[bot]

capistrano-scm-git_with_submodule_and_resolv_symlinks.gemspec

@@ -23,5 +23,5 @@ Gem::Specification.new do |spec|
   spec.add_development_dependency "bundler"
   spec.add_development_dependency "rake"
   spec.add_development_dependency "rspec", "~> 3.0"
-  spec.add_development_dependency "mocha", "~> 2.1"
+  spec.add_development_dependency "mocha", "~> 3.0"
 end