[CORD-3176]

Have API docs generation die if virtualenv not installed

Change-Id: Ia2f5890b5659aec5049368c162635e52fbd68b67
diff --git a/docs/Makefile b/docs/Makefile
index 536170d..08c6179 100644
--- a/docs/Makefile
+++ b/docs/Makefile
@@ -3,11 +3,13 @@
 swagger: swagger_clean swagger_docs swagger_serve_spec
 
 venv-xosdocs:
-	bash venv-xosdocs.sh
+	./venv-xosdocs.sh
 
 swagger_docs: venv-xosdocs
 	bash -c 'source $(DOCSDIR)venv-xosdocs/bin/activate && python $(DOCSDIR)scripts/swagger_docs.py'
 
+clean: swagger_clean venv_clean
+
 swagger_clean:
 	rm -rf swagger/specs/*