Eventually, To start GRPC server, enable env flag:
  OPENMOCK_GRPC_ENABLED=true

Currently does not run a server.
Some options for running might come up:
  a) should individual mockr/openmock servers spin up with a given
     protofile as required for testing
  b) should the mockr/openmock service be configured to spin up new
     grpc services on demand via recieving a protofile over http.
     would the grpc service spin down on recieving a request to halt
     a previously created grpc? Is there something that does this?

Right now, the simplest thing is option a), and is to give openmock
a protofile on start and start the service(s). this is how gripmock works

the new venctor participle is used for parsing the protofiles
so we can extract information we need to generate the stubs