fix(types): fix space.d.ts

Fixes #229

Author: Khaledgarbaya

typings/space.d.ts

@@ -13,7 +13,7 @@ import { UIExtension, UIExtensionProps } from './uiExtension'
 import { Upload } from './upload'
 import { Stream } from 'stream'
 import { QueryOptions } from './queryOptions'
-import { Snapshot } from 'when'
+import { Snapshot } from './snapshot'
 import { EditorInterface } from './editorInterface'
 import { WebhookProps, WebHooks } from './webhook'
 import { PreviewApiKey } from './previewApiKey'