title: Cannot use environment variable in Circleci orb
body: <p>I am trying to create a Circleci workflow which builds and uploads a java WAR to my organizations existing S3 artifact storage bucket repository. First, the project is built and some information is saved in a file, as well as VERSION being put into BASH_ENV:</p>
  
  <pre><code>export "VERSION=$(mvn -q -Dexec.executable=echo -Dexec.args='${project.version}' --non-recursive exec:exec)" &gt;&gt; $BASH_ENV
    if [ $CIRCLE_BRANCH = "master" ]; then
      ENVIRONMENT=production
    elif [ $CIRCLE_BRANCH = "develop" ]; then
       ENVIRONMENT=qa
    elif [ $CIRCLE_BRANCH = "release-1.0" ]; then
       ENVIRONMENT=staging
    else
       ENVIRONMENT=$CIRCLE_BRANCH
    fi
  
    echo "ENVIRONMENT=$ENVIRONMENT" &gt;&gt; project.info
    if [ -z "$ENVIRONMENT" ]; then
      echo No environment is set
    exit 1
      fi
  </code></pre>
  
  <p>Then, I attempt to upload the artifact using the official S3 orb:</p>
  
  <pre><code>    steps:
        - attach_workspace:
            at: .
        - run: source project.info
        - run: export "VERSION=$VERSION" &gt;&gt; $BASH_ENV
        - aws-s3/copy:
            from: target/project-${VERSION}.war
            to: 's3://artifact.bucket/project/project-${VERSION}.war'
            arguments: '--dryrun'
  </code></pre>
  
  <p>This upload task fails with <code>The user-provided path target/project-.war does not exist.</code> Because an empty string is being interpolated instead of the expected version.</p>
  
  <p>The Circleci documentation states:</p>
  
  <blockquote>
    <p>In every step, CircleCI uses bash to source BASH_ENV. This means that BASH_ENV is automatically loaded and run, allowing you to use interpolation and share environment variables across run steps.</p>
  </blockquote>
  
  <p>Yet it appears that this is not the case. How do I make the S3 upload tasks use the environment variables I am setting?</p>