README: Drop dead JavaScript alternatives (#904)

All listed javascript alternatives are dead. Talkback is alive.

README.md

@@ -129,10 +129,7 @@ yard server --reload
   * [HAVCR](https://github.com/cordawyn/havcr) (Haskell)
   * [Mimic](https://github.com/acoulton/mimic) (PHP/Kohana)
   * [PHP-VCR](https://github.com/php-vcr/php-vcr) (PHP)
-  * [Nock-VCR](https://github.com/carbonfive/nock-vcr) (JavaScript/Node)
-  * [Sepia](https://github.com/linkedin/sepia) (JavaScript/Node)
-  * [VCR.js](https://github.com/elcuervo/vcr.js) (JavaScript)
-  * [yakbak](https://github.com/flickr/yakbak) (JavaScript/Node)
+  * [Talkback](https://github.com/ijpiantanida/talkback) (JavaScript/Node)
   * [NSURLConnectionVCR](https://bitbucket.org/martijnthe/nsurlconnectionvcr) (Objective-C)
   * [VCRURLConnection](https://github.com/dstnbrkr/VCRURLConnection) (Objective-C)
   * [DVR](https://github.com/venmo/DVR) (Swift)