Add missing version.go file.

authority/version.go

@@ -0,0 +1,17 @@
+package authority
+
+// GlobalVersion stores the version information of the server.
+var GlobalVersion = Version{
+	Version: "0.0.0",
+}
+
+// Version defines the
+type Version struct {
+	Version                     string
+	RequireClientAuthentication bool
+}
+
+// Version returns the version information of the server.
+func (a *Authority) Version() Version {
+	return GlobalVersion
+}