Remove that api/ directory as we don't need it right now

- I think it's something we can implement at a later time

api/3.json

-{
-  "version": "3.3.7",
-  "themes": [
-    {
-      "name": "Masonstrap",
-      "description": "Easily provide any web project with Mason branding",
-      "thumbnail": "https://bootswatch.com/cerulean/thumbnail.png",
-      "preview": "https://bootswatch.com/cerulean/",
-      "css": "https://bootswatch.com/cerulean/bootstrap.css",
-      "cssMin": "https://bootswatch.com/cerulean/bootstrap.min.css",
-      "cssCdn": "https://maxcdn.bootstrapcdn.com/bootswatch/latest/cerulean/bootstrap.min.css",
-      "less": "https://bootswatch.com/cerulean/bootswatch.less",
-      "lessVariables": "https://bootswatch.com/cerulean/variables.less",
-      "scss": "https://bootswatch.com/cerulean/_bootswatch.scss",
-      "scssVariables": "https://bootswatch.com/cerulean/_variables.scss"
-    }
-  ]
-}