testservice: Create initial testservice executable

This CL will create an initial testservice executable.
This executable does not actual provision DUT or run tests. Those will
implement in future. For this CL, it will only start a TestService
server to listen to requests and log its status.

Run following command in chroot to build the executable
cd ~/trunk/src/platform/dev/test; ./fast_build.sh

Example:
 $ ./fast_build.sh
Start building: /home/seewaifu/go/pkg chromiumos/testservice/cmd/testservice /home/seewaifu/go/bin/testservice

$ ~/go/bin/testservice
2021/05/08 00:25:58 Starting testservice version <unknown>
2021/05/08 00:25:58 testservice listen to request at [::]:44273

$ ls /tmp/testservice/
20210507-171818  20210507-172003  20210507-172501  20210507-172558  log

$ cat /tmp/testservice/20210507-172558/log.txt
2021/05/08 00:25:58 Starting testservice version <unknown>
2021/05/08 00:25:58 testservice listen to request at [::]:44273

Unit Test Result
$ ./fast_build.sh -T
ok  	chromiumos/testservice/cmd/testservice	(cached)

BUG=b:187556761
TEST=./fast_build.sh -T; ./fast_build.sh; ~/go/bin/testservice

Change-Id: Ic8fe53dc125f6aced4fdbf5c846ee78b08eaec97
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/dev-util/+/2881276
Tested-by: Seewai Fu <seewaifu@google.com>
Commit-Queue: Seewai Fu <seewaifu@google.com>
Reviewed-by: Katherine Threlkeld <kathrelkeld@chromium.org>
Reviewed-by: C Shapiro <shapiroc@chromium.org>
4 files changed