minor refactoring

output.csv

src/main/java/sma/agents/Agent.java

src/main/java/sma/agents/RandomWalkingAgent.java

src/main/java/sma/agents/states/ExposedState.java

src/main/java/sma/agents/states/InfectedState.java

src/main/java/sma/agents/states/RecoveredState.java

src/main/java/sma/agents/states/SuceptibleState.java

src/main/java/sma/scheduler/FairAsynchronousScheduler.java

src/main/java/sma/scheduler/FairSynchronousScheduler.java