Travis: Don't test on Ruby 1.8 (it's deprecated, and it breaks the build)
Switch from the test-construct gem (deprecated) to test_construct
Add a rubocop todo-style config created by "--auto-gen-config" and inherit it
Fix an issue reported by rubocop that wasn't ignored in the todo config

Issue text: Favor modifier if/unless usage when you have a single-line body.
Fix several rubocop issues with "rubocop -a"
Fix a few more syntax-related rubocop issues manually
Add brief documentation comments for Homesick and Homesick::Actions
Rename the todo config to .rubocop.yml, now that more rubocop issues are fixed
Add todo comments to the rubocop config
Swap some if/else statements so the positive case is always first
Add and use a new smart_say_status method that wraps say_status
Add and use a new smart_system method that wraps system
Refactor the clone method to decrease its cyclomatic complexity
Fix some broken spec expectations and move/rename a method
Refactor the ln_s method to decrease its cyclomatic complexity
Wrap all lines of Ruby code to 79 characters (maximum)
Separate the action handling of ln_s into a new method to lower complexity