Travis CLI installation
The first prerequisite to install Travis CLI is to have Ruby (https://www.ruby-lang.org/en/documentation/installation/) installed on your OS and make sure that it is version 1.9.3 or greater.
You can check that you have Ruby installed by running the following command in a command shell or Terminal:

Windows installation
The Travis CLI user documentation at https://github.com/travis-ci/travis.rb#windows recommends that you use the RubyInstaller (http://rubyinstaller.org/) to install the latest version of Ruby on the Windows OS.
We need to pick Ruby Devkit version 2.5.1 at the RubyInstaller download site and then make sure to accept the license agreement and then choose the appropriate options for the installation. Make sure to install the development toolchain.
When the installer window closes, a Command Prompt will open and you will need to pick an option; you can just hit enter to install all three options on your system. The installation process could take a while to...