Generator does not delete files for items removed from API spec

[algochoi]

Subject of the issue

Your environment

@jasonpaulos reported that the generator only writes/appends items from the spec. If something was removed from the API spec, the old files would not be deleted.

Steps to reproduce

Investigate example later.

Expected behaviour

For removed items from the spec, the corresponding generated file should also be removed. We could run something like a clean command before running the generator to make sure that all stale files are removed first, and the generator is then run to generate the files according the the API spec.

Actual behaviour

[algochoi]

#47 #50 #51 Addresses this issue