remove data dirs in make clean and updated gitignore with api/data

.gitignore

@@ -50,3 +50,4 @@ web/sass-files/sass/.sass-cache/
 
 # Default local file storage
 data/*
+api/data/*

Makefile

@@ -112,6 +112,8 @@ clean:
 	rm -f web/static/js/bundle*.js
 	rm -f web/static/css/styles.css
 
+	rm -rf data/*
+	rm -rf api/data/*
 	rm -rf logs/*