added expect in travis

.travis.yml

@@ -1,10 +1,26 @@
 language: node_js
 
 node_js:
+  - "5"
   - "6"
 
+matrix:
+  include:
+    - os: linux
+      services: docker
+      env: CONTAINER=ubuntu:latest
+    - os: osx
+
 sudo: false
+
+before_install:
+    - if [[ "$TRAVIS_OS_NAME" == "linux"                      ]] ; then sudo apt-get -qq update        ; fi
+    - if [[ "$TRAVIS_OS_NAME" == "linux" && ! $(which expect) ]] ; then sudo apt-get install -y expect ; fi
+    - if [[ "$TRAVIS_OS_NAME" == "osx"                        ]] ; then brew update                    ; fi
+    - if [[ "$TRAVIS_OS_NAME" == "osx"   && ! $(which expect) ]] ; then brew install expect            ; fi
+
 script:
     - "npm run test"
     - "bash ./scripts/gen.sh"
+
 after_script: "npm install coveralls && cat ./coverage/lcov.info | ./node_modules/coveralls/bin/coveralls.js && rm -rf ./coverage"