Envoy-data-plane

* Upgraded betterproto to 2.0.0b5
* Updated protos to 1.25.0

What's Changed
* Keeping protobufs up to date in the pypi package by cetanu in https://github.com/cetanu/envoy_data_plane/pull/14


**Full Changelog**: https://github.com/cetanu/envoy_data_plane/compare/0.3.0...0.4.0

Updated master branch to envoy 1.21.0 protobufs

* Added prometheus protobufs
* Script now compiles all protobufs at once, instead of incrementally, which should result in less inconsistency
* Converted the project to use github actions instead of travis

Bumped betterproto to 2.0.0b3 which should allow creating a grpc server using service base classes