Small update to add configurable Hotkeys to the game and to change the Gauntlet

• Hotkeys can now be changed for spells 1-5 in the settings (Default keys 1-5)
• Hotkeys for Inventory (I), Spells(S) and Stat Points (P) can also be changed in the settings
• Hotkeys for spells now appear on screen
• Upgraded engine to Unity 5.6
• Fixed pathing hole in Mountain Path run
• Snowy rocks visuals changed in Cold North run
• Fixed performance issue with 'Wind Spirit' enemy
• The Gauntlet layout has been redone
• Gauntlet size is about 75% smaller
• Gauntlet now spawns 35 enemies per wave (down from 50)
• Gauntlet changes should mean less walking and more fighting, also benefits area of effect skills more