Export fixture state types (#938)

Author: ovidiuch

packages/react-cosmos-fixture/src/index.ts

@@ -4,6 +4,8 @@ export { PostMessage } from './FixtureConnect/PostMessage';
 export { WebSockets } from './FixtureConnect/WebSockets';
 
 // Use in decorators
+export { FixtureState } from 'react-cosmos-shared2/fixtureState';
+export { SetFixtureState } from './shared';
 export { FixtureContext } from './FixtureContext';
 
 // Advanced: Use in fixtures to capture elements in render callback