fix: re-export notification types (#130)

Author: Aaron Cook

src/index.ts

@@ -32,6 +32,7 @@ export * from './types/common'
 export * from './types/master-copies'
 export * from './types/decoded-data'
 export * from './types/safe-messages'
+export * from './types/notifications'
 
 // Can be set externally to a different CGW host
 let baseUrl: string = DEFAULT_BASE_URL