feat(cicd): add .travis.yml file (#9)

.travis.yml

@@ -0,0 +1,14 @@
+sudo: false
+language: node_js
+matrix:
+  fast_finish: true
+  include:
+    - node_js: '10'
+# https://github.com/greenkeeperio/greenkeeper-lockfile#npm
+before_install:
+# package-lock.json was introduced in npm@5
+- '[[ $(node -v) =~ ^v9.*$ ]] || npm install -g npm@latest' # skipped when using node 9
+- npm install -g greenkeeper-lockfile
+before_script: greenkeeper-lockfile-update
+after_script: greenkeeper-lockfile-upload
+install: npm install