• download GPG key from https://bintray.com/user/downloadSubjectPublicKey?username=bintray to ~/Downloads/bintray-public.key.asc
• sudo apt-key add ~/Downloads/bintray-public.key.asc
• add 'deb https://dl.bintray.com/kafeg/otus trusty main' to /etc/apt/sources.list
• sudo apt-get update
• sudo apt-get install helloworld