title: Is there a way to change directory on AWS codebuild
body: <p>With Snap-CI going away I've been trying to get our builds working on AWS CodeBuild. I have my buildspec.yml built out, but changing directories doesn't seem to work.</p>
  
  <pre><code>version: 0.1
  
  phases:
    install:
      commands:
        - apt-get update -y
        - apt-get install -y node
        - apt-get install -y npm
    build:
      commands:
        - cd MyDir  //Expect to be in MyDir now
        - echo `pwd` //Shows /tmp/blablabla/ instead of /tmp/blablabla/MyDir
        - npm install //Fails because I'm not in the right directory
        - bower install
        - npm run ci
    post_build:
      commands:
        - echo Build completed on `date`
  artifacts:
    files:
      - MyDir/MyFile.war
    discard-paths: yes
  </code></pre>
  
  <p>It seems like this should be fairly simple, but so far I haven't had any luck getting this to work.</p>