Add test cases for alternate zero zone offsets

Author: schlosna

datetime/src/test/java/com/fasterxml/jackson/datatype/jsr310/deser/InstantDeserTest.java

@@ -434,6 +434,30 @@ public void testDeserializationFromStringWithZeroZoneOffset03() throws Exception
         assertEquals("The value is not correct.", date, result);
     }
 
+    @Test
+    public void testDeserializationFromStringWithZeroZoneOffset04() throws Exception {
+        Instant date = Instant.now();
+        String json = formatWithZeroZoneOffset(date, "+00:30");
+        Instant result = READER.readValue(json);
+        assertNotEquals("The value is not correct.", date, result);
+    }
+
+    @Test
+    public void testDeserializationFromStringWithZeroZoneOffset05() throws Exception {
+        Instant date = Instant.now();
+        String json = formatWithZeroZoneOffset(date, "+01:30");
+        Instant result = READER.readValue(json);
+        assertNotEquals("The value is not correct.", date, result);
+    }
+
+    @Test
+    public void testDeserializationFromStringWithZeroZoneOffset06() throws Exception {
+        Instant date = Instant.now();
+        String json = formatWithZeroZoneOffset(date, "-00:00");
+        Instant result = READER.readValue(json);
+        assertEquals("The value is not correct.", date, result);
+    }
+
     private String formatWithZeroZoneOffset(Instant date, String offset){
         return '"' + FORMATTER.format(date).replaceFirst("Z$", offset) + '"';
     }