fix(operators): force add operators to emit

Author: robwormald

src/add/observable/bindCallback.ts

@@ -1,3 +1,5 @@
 import {Observable} from '../../Observable';
 import {BoundCallbackObservable} from '../../observable/bindCallback';
 Observable.bindCallback = BoundCallbackObservable.create;
+
+export var _void: void;

src/add/observable/defer.ts

@@ -1,3 +1,5 @@
 import {Observable} from '../../Observable';
 import {DeferObservable} from '../../observable/defer';
 Observable.defer = DeferObservable.create;
+
+export var _void: void;

src/add/observable/empty.ts

@@ -1,3 +1,5 @@
 import {Observable} from '../../Observable';
 import {EmptyObservable} from '../../observable/empty';
 Observable.empty = EmptyObservable.create;
+
+export var _void: void;

src/add/observable/forkJoin.ts

@@ -1,3 +1,5 @@
 import {Observable} from '../../Observable';
 import {ForkJoinObservable} from '../../observable/forkJoin';
 Observable.forkJoin = ForkJoinObservable.create;
+
+export var _void: void;

src/add/observable/from.ts

@@ -1,3 +1,5 @@
 import {Observable} from '../../Observable';
 import {FromObservable} from '../../observable/from';
 Observable.from = FromObservable.create;
+
+export var _void: void;

src/add/observable/fromArray.ts

@@ -2,3 +2,5 @@ import {Observable} from '../../Observable';
 import {ArrayObservable} from '../../observable/fromArray';
 Observable.fromArray = ArrayObservable.create;
 Observable.of = ArrayObservable.of;
+
+export var _void: void;

src/add/observable/fromEvent.ts

@@ -1,3 +1,5 @@
 import {Observable} from '../../Observable';
 import {FromEventObservable} from '../../observable/fromEvent';
 Observable.fromEvent = FromEventObservable.create;
+
+export var _void: void;

src/add/observable/fromEventPattern.ts

@@ -1,3 +1,5 @@
 import {Observable} from '../../Observable';
 import {FromEventPatternObservable} from '../../observable/fromEventPattern';
 Observable.fromEventPattern = FromEventPatternObservable.create;
+
+export var _void: void;

src/add/observable/fromPromise.ts

@@ -1,3 +1,5 @@
 import {Observable} from '../../Observable';
 import {PromiseObservable} from '../../observable/fromPromise';
 Observable.fromPromise = PromiseObservable.create;
+
+export var _void: void;

src/add/observable/interval.ts

@@ -1,3 +1,5 @@
 import {Observable} from '../../Observable';
 import {IntervalObservable} from '../../observable/interval';
 Observable.interval = IntervalObservable.create;
+
+export var _void: void;