Multiple instances of Exosphere with same project interfere with each other

For example, if a server is launched in one app instance, another app instance will pick it up, and try to assign a public IP address to it.

Will sometimes cause problems when two or more people on the same project happen to be using the app at the same time and one person launches a server.

More importantly this problem definitely makes Exosphere annoying to use for:

• Workshops sharing a single project
• Large projects with many users

Related issues:

• #317
  • I (Julian) think this could be the lynch-pin issue - moving our ad-hoc orchestration logic out of Elm
  • Retracted after discussion with @cmart. We definitely want basic server launch functionality to work on clouds that don't have Heat installed.
• #101
• #217 (closed)
• #282 (closed)
• #302 (closed)