Tools: Add support for environment variable

[emilbillberg]

Feature request

Add support for different environments. A good example of the feature can be found in Angular CLI:
Angular CLI Environment

Why

Projects may have different configurations in different environments.

How

In polymer-project-config add project options:

"environment": "dev|stage|prod",
"environmentSource": "environments/environment.html",
"environments": {
  "dev": "environments/environment.html",
  "stage": "environments/environment.stage.html",
  "prod": "environments/environment.prod.html"
}

[eduardosada]

I think we all want the same: https://github.com/Polymer/polymer-cli/issues/408

[mskasal]

Since there is no progress on this topic, I have to ask how do you handle environment variables in your projects with polymer build?

[stale[bot]]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.