expose IFeatureFilter (#29)

Author: zhiyuanliang-ms

src/index.ts

@@ -2,4 +2,5 @@
 // Licensed under the MIT license.
 
 export { FeatureManager } from "./featureManager";
-export { ConfigurationMapFeatureFlagProvider, ConfigurationObjectFeatureFlagProvider, IFeatureFlagProvider } from "./featureProvider";
+export { ConfigurationMapFeatureFlagProvider, ConfigurationObjectFeatureFlagProvider, IFeatureFlagProvider } from "./featureProvider";
+export { IFeatureFilter } from "./filter/FeatureFilter";