chore: add CI setup

Author: marionebl

.travis.yml

@@ -0,0 +1,8 @@
+language: node_js
+node_js:
+  - '7'
+  - '6'
+  - '4'
+before_install:
+  - npm i -g npm
+after_success: npm run coveralls

appveyor.yml

@@ -0,0 +1,21 @@
+environment:
+  matrix:
+    - nodejs_version: '7'
+    - nodejs_version: '6'
+    - nodejs_version: '4'
+install:
+  - ps: Install-Product node $env:nodejs_version
+  - set CI=true
+  - npm -g install npm@latest
+  - set PATH=%APPDATA%\npm;%PATH%
+  - npm install
+matrix:
+  fast_finish: true
+build: off
+version: '{build}'
+shallow_clone: true
+clone_depth: 1
+test_script:
+  - node --version
+  - npm --version
+  - npm test