examples: add bazel build example

[dapengzhang0]

Maven

If you prefer to use Maven:

$ mvn verify
$ # Run the server
$ mvn exec:java -Dexec.mainClass=io.grpc.examples.helloworld.HelloWorldServer
$ # In another terminal run the client
$ mvn exec:java -Dexec.mainClass=io.grpc.examples.helloworld.HelloWorldClient

Bazel

If you prefer to use Bazel:

(With Bazel v0.4.5 or above.)
$ bazel build :hello-world-server :hello-world-client
$ # Run the server:
$ bazel-bin/hello-world-server
$ # In another terminal run the client
$ bazel-bin/hello-world-client

[ejona86]

This doesn't work, because you can only have one bazel in a workspace running at a time. Instead do the following?

$ bazel build :hello-world-server :hello-world-client
$ # Run the server:
$ bazel-bin/hello-world-server
$ # In another terminal run the client
$ bazel-bin/hello-world-client

[dapengzhang0]

Ooh! Corrected and tried.