Concourse CI - develop+release+pr

[dpb587]

This PR updates/refactors/fixes pipelines so we now have a reliable pipeline for accurately testing all our branches. It also breaks down jobs/resources configuration for support of testing PRs. It adds support for creating final releases with semantic versioning as well. It also makes it easy and possible for people to monitor and use the latest passing release from our branches before creating a final release or pulling/building it locally.

I'd like to review and discuss this by hangout before merging.

I updated some README notes in a couple places. For testing, I was using the fork on my own account and a separate, mirrored bucket.

Note, I'm currently using a patched version of fly in order to support inline variable interpolation which greatly simplifies the configuration. Need to discuss and PR it upstream.

Some pipeline examples...

• develop - http://concourse.meta.logsearch.io:8080/pipelines/logsearch-develop
• release - http://concourse.meta.logsearch.io:8080/pipelines/logsearch-release
• pr (#160) - http://concourse.meta.logsearch.io:8080/pipelines/logsearch-pr160

A configuration script takes care of non-interactively pushing pipelines to concourse...

$ FLY_TARGET=cilabs-meta ./ci/bin/fly-configure 
# develop
apply configuration? (y/n): configuration updated

# release
apply configuration? (y/n): configuration updated

# pr160
apply configuration? (y/n): configuration updated

# pr163
apply configuration? (y/n): configuration updated

# pr169
apply configuration? (y/n): configuration updated

# pr170
apply configuration? (y/n): configuration updated

[dpb587]

Todo... switch back to version-bumping dev rather than completely independent versions. Continue to retain separate version files, though.