You can clone repository and run install.sh script, but it will be easier to use one-liners:

• Wget
  wget -O gclone https://raw.githubusercontent.com/rostegg/gclone/master/gclone.py && chmod +x gclone && sudo mv gclone /usr/bin/gclone
• cURL
  curl https://raw.githubusercontent.com/rostegg/gclone/master/gclone.py --output gclone && chmod +x gclone && sudo mv gclone /usr/bin/gclone