fix(types/testWithSpectron): require spectron as arg

Author: nklayman

index.d.ts

@@ -31,4 +31,4 @@ interface Server {
    Run electron:serve, but instead of launching Electron it returns a Spectron Application instance.
    Used for e2e testing with Spectron.
 */
-export function testWithSpectron(options?: Options): Promise<Server>
+export function testWithSpectron(spectron, options?: Options): Promise<Server>