Bumped drf-yasg to v1.9.2

requirements.txt

@@ -8,7 +8,7 @@ django-taggit==0.22.2
 django-taggit-serializer==0.1.7
 django-timezone-field==2.1
 djangorestframework==3.8.1
-drf-yasg[validation]==1.9.1
+drf-yasg[validation]==1.9.2
 graphviz==0.8.4
 Markdown==2.6.11
 natsort==5.3.3