Added travis CI

Signed-off-by: Jim Martens <github@2martens.de>

.travis.yml

@@ -0,0 +1,24 @@
+language: ruby
+rvm:
+- 2.3.3
+addons:
+  ssh_known_hosts: wolf.uberspace.de
+env:
+  global:
+  - NOKOGIRI_USE_SYSTEM_LIBRARIES=true
+sudo: false
+script: jekyll build && htmlproofer ./_site
+before_deploy:
+- openssl aes-256-cbc -K $encrypted_518a90de15e0_key -iv $encrypted_518a90de15e0_iv
+  -in deploy_ed25519.enc -out deploy_ed25519 -d
+- eval "$(ssh-agent -s)"
+- chmod 600 /tmp/deploy_ed25519
+- ssh-add /tmp/deploy_ed25519
+deploy:
+  provider: script
+  skip_cleanup: true
+  script:
+    - rsync -r --delete-after --quiet $TRAVIS_BUILD_DIR/.ssh martens7@wolf.uberspace.de:tmp/$TRAVIS_BUILD_ID
+    - ssh martens7@wolf.uberspace.de rm -rf tmp/old.build && mkdir tmp/old.build && mv html/* tmp/old.build/ && mv tmp/$TRAVIS_BUILD_ID/* html/
+  on:
+    branch: master