Add super admin validation

Resolves #24

server/utils/validateSuperAdmin.go

@@ -0,0 +1,15 @@
+package utils
+
+import (
+	"github.com/gin-gonic/gin"
+	"github.com/yauthdev/yauth/server/constants"
+)
+
+func IsSuperAdmin(gc *gin.Context) bool {
+	secret := gc.Request.Header.Get("x-yauth-admin-secret")
+	if secret == "" {
+		return false
+	}
+
+	return secret == constants.YAUTH_ADMIN_SECRET
+}