Support multiple controllers paths

[salmanasiddiqui]

What? Why?

I ran into a problem in a Rails app which was made up of multiple Rails engines. The problem was that two engines were using Gruf and when they were used in same Rails app, the Gruf config for controllers_path was getting overridden.

So to fix that problem, I patched Gruf to support multiple paths for controllers by adding a new config field controllers_paths. This field defaults to [controllers_path]. Gruf uses this controllers_paths instead of controllers_path everywhere, but controllers_path is kept in config for backward compatibility.

Note: I think the config should support something like add_controllers_paths, instead of directly setting controllers_paths. That will allow multiple modules to add their controllers path without messing with the existing paths. Let me know if you like this idea, I will update the PR

How was it tested?

All the specs are passing

[splittingred]

Hi @salmanasiddiqui - while this is a good change to support multiple paths, this unfortunately makes a backwards incompatible change here I'd like to avoid.

Can we add this as a new keyword argument, and deprecate the old one (to be removed in gruf 3.0). We should support both syntaxes in 2.x.