COMBAT: Win/Lose conditions and minor bugs

[aelmosalamy]

• [x] After using command the visual list of available enemies to attack updates, but the actual list of enemies available doesn't update, giving the ability to attack a dead enemy.
• [x] The game loop correctly check for enemies state - dead or alive - checking user state needs to be implemented along with win and lose output screens.
• [x] Actions needs to be created and printed inside the combat.Combat.display() function e. g 'Minion hit you' or 'You zapped an enemy'