Specflow - how to create steps in another assembly
For some reason having steps in another assembly doesn't always work. When I tried this I found out there is a bug with specflow, that if you don't put your step class in the root of the assembly, it might not bind it correctly. So, place your step class directly in the root (not in a sub-folder).
Also, in the app.config of your project with your feature files you need to have this configuration