feat(publish): recover from network failure

[fahslaj]

Description

Catches the EPUBLISHCONFLICT error from npm when a version already exists. In this case, Lerna assumes that you have already published the package.

Motivation and Context

This allows lerna publish from-git to be idempotent. If one or more packages fail to publish, then you can rerun lerna publish from-git to publish the packages that failed.

#455

How Has This Been Tested?

This has been tested manually and is covered by e2e tests.

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)
• Chore (change that has absolutely no effect on users)

Checklist:

• My code follows the code style of this project.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I have read the CONTRIBUTING document.
• I have added tests to cover my changes.
• All new and existing tests passed.