(build) Fixing security warning

Author: gep13

Source/GitReleaseManager/packages.config

@@ -1,5 +1,5 @@
 <?xml version="1.0" encoding="utf-8"?>
 <packages>
   <package id="Octokit" version="0.29.0" targetFramework="net451" />
-  <package id="YamlDotNet" version="4.3.1" targetFramework="net451" />
-</packages>
+  <package id="YamlDotNet" version="5.0.0" targetFramework="net451" />
+</packages>