Consider changing API for clarity

[stanleyrya]

This issue is not 100% necessary, however I found it confusing that you are able to get a list of molecule listings from the database with GET /:name and a specific molecule file with GET /files/:filename.

To play devil's advocate, the GET /files/:filename request should only be called by using a URL given to you.

Long story short: look into this and let me know what you think either way!