Fix PotD rule not being shown
Merge pull request #868 from Slayer95/master

Fix PotD rule not being shown
Proper fail message for Sky Drop
Fix Sky Drop

Sky drop wasn't converted to the new two-turn move system like
other moves, so it couldn't be targeted.
Remove Lava Plume from Flareon's viable moves
Update gen 1 and 2 learnsets

- Deleted gen 1 learnsets as it inherits from gen 2
- The move Return was not in quotation marks
Add viable moves for Mega Heracross