Add rest put mapping test with dot in fieldname

rest-api-spec/src/main/resources/rest-api-spec/test/indices.put_mapping/10_basic.yaml

@@ -17,6 +17,8 @@
               text2:
                 type:     text
                 analyzer: whitespace
+              subfield.text3:
+                type:     text
 
   - do:
       indices.get_mapping:
@@ -47,4 +49,5 @@
         index: test_index
   
   - match: {test_index.mappings.test_type.properties.text1.type:     text}
+  - match: {test_index.mappings.test_type.properties.subfield.properties.text3.type:     text}
   - match: {test_index.mappings.test_type.properties.text1.fields.text_raw.type: keyword}