fix: export Runner, not just its type. (#4227)

lib/index.ts

@@ -4,7 +4,6 @@ import {ProtractorExpectedConditions} from './expectedConditions';
 import {ProtractorBy} from './locators';
 import {PluginConfig, ProtractorPlugin} from './plugins';
 import {Ptor} from './ptor';
-import {Runner} from './runner';
 
 // Re-export selenium-webdriver types.
 export {ActionSequence, Browser, Builder, Button, Capabilities, Capability, error, EventEmitter, FileDetector, Key, logging, promise, Session, until, WebDriver, WebElement, WebElementPromise} from 'selenium-webdriver';
@@ -15,8 +14,8 @@ export {ElementArrayFinder, ElementFinder} from './element';
 export {ProtractorExpectedConditions} from './expectedConditions';
 export {ProtractorBy} from './locators';
 export {Ptor} from './ptor';
+export {Runner} from './runner';
 
-export type Runner = Runner;
 export type PluginConfig = PluginConfig;
 export type ProtractorPlugin = ProtractorPlugin;