Fixed when roost removes flying type (#148)

* Initial push with roost fix

* Roost fix

* Added GROUNDED to Levitate

* Cleaned up GROUNDED code

src/data/enums/battler-tag-type.ts

@@ -47,5 +47,6 @@ export enum BattlerTagType {
   IGNORE_ACCURACY = "IGNORE_ACCURACY",
   BYPASS_SLEEP = "BYPASS_SLEEP",
   IGNORE_FLYING = "IGNORE_FLYING",
+  GROUNDED = "GROUNDED", 
   SALT_CURED = "SALT_CURED"
 }