BW: Ban Cloyster from OU (smogon#10287)

https://www.smogon.com/forums/threads/bw-ou-cloyster.3742769/page-2#post-10105940

Author: shrianshChari

data/mods/gen5/formats-data.ts

@@ -339,7 +339,7 @@ export const FormatsData: {[k: string]: ModdedSpeciesFormatsData} = {
 		tier: "LC",
 	},
 	cloyster: {
-		tier: "OU",
+		tier: "Uber",
 		doublesTier: "DOU",
 	},
 	gastly: {