doc: add Gibson Fahnestock to Release team

Refs: nodejs/TSC#350

Author: gibfahn

README.md

@@ -535,6 +535,8 @@ Node.js releases are signed with one of the following GPG keys:
 `94AE36675C464D64BAFA68DD7434390BDBE9B9C5`
 * **Evan Lucas** <evanlucas@me.com>
 `B9AE9905FFD7803F25714661B63B535A4C206CA9`
+* **Gibson Fahnestock** <gibfahn@gmail.com>
+`77984A986EBC2AA786BC0F66B01FBB92821C587A`
 * **Italo A. Casas** <me@italoacasas.com>
 `56730D5401028683275BD23C23EFEFE93C4CFFFE`
 * **James M Snell** <jasnell@keybase.io>
@@ -556,6 +558,7 @@ gpg --keyserver pool.sks-keyservers.net --recv-keys DD8F2338BAE7501E3DD5AC78C273
 gpg --keyserver pool.sks-keyservers.net --recv-keys C4F0DFFF4E8C1A8236409D08E73BC641CC11F4C8
 gpg --keyserver pool.sks-keyservers.net --recv-keys B9AE9905FFD7803F25714661B63B535A4C206CA9
 gpg --keyserver pool.sks-keyservers.net --recv-keys 56730D5401028683275BD23C23EFEFE93C4CFFFE
+gpg --keyserver pool.sks-keyservers.net --recv-keys 77984A986EBC2AA786BC0F66B01FBB92821C587A
 ```
 
 See the section above on [Verifying Binaries](#verifying-binaries) for details