Add enemies for Level 2

[Lj Miranda]

To-do:

• Create Art
  • Skeleton Swordsman
  • Skeleton Rogue
  • Skeleton Defender
• Refactor EnemyFactory to use custom movement and attacks
• Implement Defend Mechanic

Rogue actually does an evade, but I will just lump it with the defend mechanic. For defender, defend causes 80% damage reduction but 90% less damage.