add templates for redis

[karthik2804]

This should probably be merged after #287 and bump the versions in the templates.

[karthik2804]

Are we okay with expecting a user to implement the class and export an object? If not, we could potentially add a spin.ts as we do for the http templates and wrap all that up where the user can just export one function.

[radu-matei]

Given they're technically part of the same SDK, I'd like the two to be consistent.

[karthik2804]

One part I would like to note though is that - the http handler uses the built in fetchEvent while redis and anything else would end up using generated bindings.