docs: Add promotive.es to the showcase

docs/content/showcase/promotive.md

@@ -0,0 +1,15 @@
+---
+date: 2017-02-21T12:26:26+01:00
+description: "Corporate website a event management agency"
+license: ""
+licenseLink: ""
+sitelink: https://promotive.es
+tags:
+- company
+- corporate
+- spanish
+- event management
+- bootstrap
+thumbnail: /img/promotive.png
+title: Promotive
+---