I downloaded Postman for Linux (from https://www.getpostman.com/apps), unpacked .tar.gz file into ~/bin/postman and then tried to execute ~/bin/postman/Postma
~/bin/postman
~/bin/postman/Postma
also you need install nodejs:
curl -sL https://deb.nodesource.com/setup_6.x | sudo -E bash - sudo apt-get install -y nodejs