Only match .elm ending files in migrations

Author: supermario

extra/Lamdera/Evergreen.hs

@@ -30,7 +30,7 @@ findMigrationFilePaths :: FilePath -> IO [FilePath]
 findMigrationFilePaths root = do
   debug_ $ "Reading src/Evergreen/Migrate to determine migrationSequence"
   paths <- safeListDirectory $ root </> "src/Evergreen/Migrate"
-  let migrationFilePaths = paths & filter (\p -> not $ ".bk" `isInfixOf` p)
+  let migrationFilePaths = paths & filter (\p -> ".elm" `isSuffixOf` p)
   debug_ $ "migrationFilePaths:" <> show migrationFilePaths
   pure migrationFilePaths