image build: add .travis.yml file for Travis automated builds

.travis.yml

@@ -0,0 +1,60 @@
+sudo: required
+language: generic
+services:
+  - docker
+env:
+  global:
+    - DOCKER="goldarte/img-tool:v0.5"
+    - TARGET_REPO="https://github.com/${TRAVIS_REPO_SLUG}.git"
+    - if [[ -z ${TRAVIS_TAG} ]]; then IMAGE_VERSION="${TRAVIS_COMMIT}}"; else IMAGE_VERSION="${TRAVIS_TAG}"; fi
+    - IMAGE_NAME="$(basename -s '.git' ${TARGET_REPO})_${IMAGE_VERSION}.img"
+git:
+  depth: 50
+jobs:
+  fast_finish: true
+  include:
+    - stage: Build
+      name: "Clever Modified Image Build"
+      cache:
+        directories:
+        - imgcache
+      before_script:
+        - docker pull ${DOCKER}
+# Check if there are any cached images, copy them to our "images" directory
+        - if [ -n "$(ls -A imgcache/*.zip)" ]; then mkdir -p images && cp imgcache/*.zip images; fi
+      script:
+        - docker run --privileged --rm -v /dev:/dev -v $(pwd):/mnt -e TRAVIS_TAG="${TRAVIS_TAG}" ${DOCKER}
+      before_cache:
+        - cp images/*.zip imgcache
+      before_deploy:
+        # Set up git user name and tag this commit
+        - git config --local user.name "goldarte"
+        - git config --local user.email "goldartt@gmail.com"
+        - sudo chmod -R 777 *
+        - cd images && zip ${IMAGE_NAME}.zip ${IMAGE_NAME}
+      deploy:
+        provider: releases
+        api_key: ${GITHUB_OAUTH_TOKEN}
+        file: ${IMAGE_NAME}.zip
+        skip_cleanup: true
+        on:
+          tags: true
+        draft: true
+        name: ${TRAVIS_TAG}
+
+    - stage: Annotate
+      name: Auto-generate changelog
+      language: python
+      python: 3.6
+      install:
+        - pip install GitPython PyGithub
+      script:
+        - PYTHONUNBUFFERED=1 python ./gen_changelog.py
+stages:
+  - Build
+  - Annotate
+# More info there
+# https://github.com/travis-ci/travis-ci/issues/6893
+# https://docs.travis-ci.com/user/customizing-the-build/
+# https://docs.travis-ci.com/user/deployment/releases
+# https://docs.travis-ci.com/user/environment-variables/