Guard against attempted deletion of inexistent attributes

Fixes #76

src/drf_yasg/generators.py

@@ -356,9 +356,9 @@ class OpenAPISchemaGenerator(object):
 
         view_inspector = view_inspector_cls(view, path, method, components, request, overrides)
         operation = view_inspector.get_operation(operation_keys)
-        if set(operation.consumes) == set(self.consumes):
+        if 'consumes' in operation and set(operation.consumes) == set(self.consumes):
             del operation.consumes
-        if set(operation.produces) == set(self.produces):
+        if 'produces' in operation and set(operation.produces) == set(self.produces):
             del operation.produces
         return operation
 

src/drf_yasg/inspectors/field.py

@@ -89,9 +89,9 @@ class InlineSerializerInspector(SerializerInspector):
                     properties=properties,
                     required=required or None,
                 )
-                if not ref_name:
+                if not ref_name and 'title' in result:
                     # on an inline model, the title is derived from the field name
-                    # but is visually displayed like the model named, which is confusing
+                    # but is visually displayed like the model name, which is confusing
                     # it is better to just remove title from inline models
                     del result.title
                 return result