Use build args to capture build time data

[jchauncey]

Acceptance Criteria:

• Use the --build-args flag when running docker build to pass in the following items (and more if needed)
• BUILD_DATE
• VERSION

You will need to do the following in the dockerfile to persist the data into the image:

ARG VERSION
ARG BUILD_DATE
ENV VERSION $VERSION
ENV BUILD_DATE $BUILD_DATE

[Cryptophobia]

This issue was moved to teamhephy/fluentd#6