如何构建/安装Travis Build？

如自述文件中“用作CLI的加载项”部分所述，以下内容对我有用：

• git clone将存储库放入某个持久目录（~/GitHub对我而言）
• 从~/GitHub/travis-build我所用ln -s $(pwd) ~/.travis/travis-build（取几乎是逐字自述）

• 运行后travis（无参数），我得到以下输出：

  nabijaczleweli@klusikomp-vm:~/.travis$ travis
  Usage: travis COMMAND ...
  
  Available commands:
  
          accounts       displays accounts and their subscription status
          branches       displays the most recent build for each branch
          cache          lists or deletes repository caches
          cancel         cancels a job or build
          compile        compiles a build script from .travis.yml
          console        interactive shell
          disable        disables a project
          enable         enables a project
          encrypt        encrypts values for the .travis.yml
          encrypt-file   encrypts a file and adds decryption steps to .travis.yml
          endpoint       displays or changes the API endpoint
          env            show or modify build environment variables
          help           helps you out when in dire need of information
          history        displays a projects build history
          init           generates a .travis.yml and enables the project
          lint           display warnings for a .travis.yml
          login          authenticates against the API and stores the token
          logout         deletes the stored API token
          logs           streams test logs
          monitor        live monitor for what's going on
          open           opens a build or job in the browser
          pubkey         prints out a repository's public key
          raw            makes an (authenticated) API call and prints out the result
          report         generates a report useful for filing issues
          repos          lists repositories the user has certain permissions on
          requests       lists recent requests
          restart        restarts a build or job
          settings       access repository settings
          setup          sets up an addon or deploy target
          show           displays a build or job
          sshkey         checks, updates or deletes an SSH key
          status         checks status of the latest build
          sync           triggers a new sync with GitHub
          token          outputs the secret API token
          version        outputs the client version
          whatsup        lists most recent builds
          whoami         outputs the current user
  
  run `/usr/local/bin/travis help COMMAND` for more infos
  

请注意其中的第10行：compile compiles a build script from .travis.yml，表明它确实起作用。