Add missing Builder test

Author: garydgregory

src/test/java/org/apache/commons/cli/OptionTest.java

@@ -107,6 +107,11 @@ public void testAddValue() {
         assertThrows(IllegalArgumentException.class, () -> option.processValue(""));
     }
 
+    @Test
+    public void testBuilderEmpty() {
+        assertThrows(IllegalArgumentException.class, () -> Option.builder().build());
+    }
+
     @Test
     public void testBuilderInsufficientParams1() {
         assertThrows(IllegalArgumentException.class, () -> Option.builder().desc("desc").build());