[Utility] Mark release branch as a non-development version.

Author: ddunbar

Sources/Utility/Versioning.swift

@@ -81,7 +81,7 @@ public struct Versioning {
     /// The current version of the package manager.
     public static let currentVersion = SwiftVersion(
         version: (3, 0, 0),
-        isDevelopment: true,
+        isDevelopment: false,
         buildIdentifier: getBuildIdentifier())
 
     /// The list of version specific "keys" to search when attempting to load