Feature Request: InterfaceNameLower as a template variable parameter.

[hohmannr]

Feature Request

I would like to see the addition of a template config variable called InterfaceNameLower, so that one could achieve more go standard library-esque file names for the mocks generated by mockery. The standard library primarily uses lowercase filenames for camelcased structs (e.g. fakeDB). To achieve the same with mockery, I would like to have the following configuration setup:

inpackage: True
filename: "{{.InterfaceNameLower}}_mock.go"
dir: "{{.InterfaceDir}}"
mockname: "Mock{{.InterfaceName}} "
packages:
  github.com/me/my-repo/pkg/datastore:
    interfaces:
      EventStorer:

This would the achieve that the following mock file is created: pkg/datastore/eventstorer_mock.go

I have not connected a PR for now, since in you state in your CONTRIBUTION guidelines to discuss the matter beforehand.
If this Feature Request will be accepted, I am willing to do the change myself and set you up with a PR. It should only be a simple change here along with a test-case that covers the new addition.

[LandonTClipp]

I have no problem at all with this, feel free to go ahead with the PR. Approved!

[hohmannr]

@LandonTClipp here you go!