Fix ts errors in strict mode

 Generic type 'Provider' requires 1 type argument(s).
Generic type 'Consumer' requires 1 type argument(s).

Author: judithhartmann

index.d.ts

@@ -7,6 +7,6 @@ declare module 'gatsby-plugin-intl' {
   export class Link<TState> extends gatsby.Link<TState> {}
   export const navigate: typeof gatsby.navigate;
   export const changeLocale: (language: string, to?: string) => void;
-  export const IntlContextProvider: React.Provider;
-  export const IntlContextConsumer: React.Consumer;
-}
+  export const IntlContextProvider: React.Provider<any>;
+  export const IntlContextConsumer: React.Consumer<any>;
+}