sudo: required
dist: trusty

language: cpp

compiler:
    - gcc

services:
    - docker

env:
    global:
        - secure: "i...=" # DOCKER_EMAIL
        - secure: "Z...=" # DOCKER_USER
        - secure: "p...=" # DOCKER_PASSWORD

<snip>

after_success:
    - docker login -e $DOCKER_EMAIL -u $DOCKER_USERNAME -p $DOCKER_PASSWORD
    - make docker-r-deliver

<snip>

Setting environment variables from .travis.yml
$ export DOCKER_EMAIL=[secure]
$ export DOCKER_USER=[secure]
$ export DOCKER_PASSWORD=[secure]

<snip>

$ docker login -e $DOCKER_EMAIL -u $DOCKER_USERNAME -p $DOCKER_PASSWORD
Password:
No output has been received in the last 10m0s, this potentially indicates a stalled build or something wrong with the build itself.
The build has been terminated