Refactor Staging/Production Alternate Host Implementation

[ronilan]

Overview

This pull request refactors the implementation of production/staging hosts (see: #533). It includes minor feature changes and is backwards compatible with any previously valid configurations.

This pull request comes "on top" of (i.e. includes changes from) #652 (which in turn comes "on top" of #651, which is "on top" of #648, #649, #650). Work is in preparation for resolving issue #654.

Change

Features

• Added development_host option. Becomes default option for publish unpublish when present.
• Changed behavior when alternate hosts are defined. Now production_host acts as alias to host. Defining staging_host or development_host is enough to default publish and unpublish away from production.
• An invalid s3_host option does not result in error and is instead silently ignored.

  Bug Fix #653

• When a chain of commands that includes publish or unpublish and host is not specifically set via command line or environment variable, all commands in the chain default away from production.

  Code

• Moved logic regarding host selection of host to versioning. This is where all user defined values from package.json are transformed into command options.

  Tests

• Tests of feature where moved from run.test.js to versioning.test.js.
• Increased test coverage for various options of using the hosts.
• All tests pass.