message: fix(flatMap): reexport flatMap as alias of mergeMap
diff: @@ -43,6 +43,7 @@ export { max } from './max';
  export { merge } from './merge';
  export { mergeAll } from './mergeAll';
  export { mergeMap } from './mergeMap';
  +export { mergeMap as flatMap } from './mergeMap';
  export { mergeMapTo } from './mergeMapTo';
  export { mergeScan } from './mergeScan';
  export { min } from './min';
  