Provide logs over HTTP, update Bobfile format, fix failing tests

[rafecolton]

Addresses:

• https://github.com/modcloth/docker-builder/issues/66 - fix parser test failures
• https://github.com/modcloth/docker-builder/issues/8 - add versioning to Bobfiles, update Bobfile format
• https://github.com/modcloth/docker-builder/issues/53 - adding http endpoint for viewing logs per
• https://github.com/modcloth/docker-builder/issues/27 - indicate how long each build took (via http logs)

Make semi-backwards-incompatible changes to the Bobfile format. Addresses a change in Go 1.3.

[jszwedko]

Diff`ed with the last commit I looked at on #78. Still looks good to me. :clap: for the integration tests.