Refactor

Component(s) to be refactored

• monkey_island.cc.resources.LocalRun
• RunOnIslandButton.js

Explanation

The UI can check if an agent is running on the island by:

1. Query /api/machines and find the ID of the island machine.
2. Query /api/agents and check if any agents are running on the island.

Tasks

• Reimplement the logic in RunOnIslandButton.componentDidMount() (0.25d) @mssalvatore
• Remove GET /api/local-monkey (0.25d) @mssalvatore