Merge pull request #1890 from alyssais/global_teardown_env

Library/Homebrew/cask/spec/cask/cli_spec.rb

Library/Homebrew/cask/spec/spec_helper.rb

Library/Homebrew/cask/test/cask/dsl_test.rb

Library/Homebrew/cask/test/test_helper.rb

Library/Homebrew/dev-cmd/tests.rb

Library/Homebrew/test/audit_test.rb

Library/Homebrew/test/commands_test.rb

Library/Homebrew/test/diagnostic_test.rb

Library/Homebrew/test/download_strategies_test.rb

Library/Homebrew/test/formula_test.rb

Library/Homebrew/test/gpg2_requirement_test.rb

Library/Homebrew/test/gpg_test.rb

Library/Homebrew/test/install_test.rb

Library/Homebrew/test/os/mac/diagnostic_test.rb

Library/Homebrew/test/sandbox_test.rb

Library/Homebrew/test/shell_test.rb

Library/Homebrew/test/support/helper/env.rb

Library/Homebrew/test/support/helper/test_case.rb

Library/Homebrew/test/tap_test.rb

Library/Homebrew/test/utils_test.rb