Mocked devhub server that uses Bootstrapper
Changes to be committed:
	new file:   src/test/java/nl/tudelft/ewi/devhub/server/MockedDevhubServer.java
	modified:   src/test/java/nl/tudelft/ewi/devhub/server/backend/Bootstrapper.java
	modified:   src/test/resources/simple-environment.json