build(deps): bump grpcio from 1.38.1 to 1.39.0

Bumps [grpcio](https://github.com/grpc/grpc) from 1.38.1 to 1.39.0.
- [Release notes](https://github.com/grpc/grpc/releases)
- [Changelog](https://github.com/grpc/grpc/blob/master/doc/grpc_release_schedule.md)
- [Commits](grpc/grpc@v1.38.1...v1.39.0)

---
updated-dependencies:
- dependency-name: grpcio
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <support@github.com>

pyproject.toml

@@ -12,7 +12,7 @@ synse_server = "synse_server.__main__:main"
 python = "^3.7"
 aiocache = "^0.11.1"
 bison = "^0.1.3"
-grpcio = "^1.38.1"
+grpcio = "^1.39.0"
 kubernetes = "^17.17.0"
 PyYAML = "^5.4.1"
 sanic = "^21.6.0"