Enhance Deployments to support flexible environments

The initial (alpha) release of Deployments only offered three fixed environments: test, staging, production.

However difference projects often have more and refer to them with different names.

For example:

• Development
• System Test
• System Integration Test
• User Acceptance Test
• Training
• Production

Having a fixed number (and named) set of deployment environments makes this otherwise desirable feature unusable since they are not going to invest in one technology to deploy to 3 environments and another for the remaining environments.