With 1.4.0 the golang/protobuf json testing protofiles
are being moved to [an internal package][1]. While this is
technically a breaking change, I doubt the maintainers
are going to reintroduce it, so I've copied the necessary
parts to our own testing protofile.
This allows users of this package and, more importantly,
grpcui to try 1.4.0 without this package having to migrate yet.
When it comes to migrating to 1.4.0, this should also make the
transition easier.
[1]: https://github.com/golang/protobuf/tree/v1.4.0-rc.4/internal/testprotos
* augments grpcurl package API in order to handle multiple formats
* deprecates old signature for InvokeRpc
* add command-line flag to use protobuf text format instead of JSON
* use AnyResolver when marshaling to/from JSON
* support go modules
- use Go 1.11 (with and without module support) in CI
- add go.mod and go.sum files
- with modules in Go 1.11, can't rely on GOPATH directory layout, so just copy test.proto into this repo
