Fix in-tree build

Align the BUILD files and build instructions in README with what's
on stable-2.14, so that the in-tree build works properly.

Change-Id: Ic29b83db510e0e09f5215aed2e76a6437d6b9c5b
diff --git a/README.md b/README.md
index 7c0340a..72adf36 100644
--- a/README.md
+++ b/README.md
@@ -51,10 +51,11 @@
    $ git clone https://gerrit.googlesource.com/plugins/owners
    $ git clone https://gerrit.googlesource.com/gerrit
    $ cd gerrit/plugins
-   $ ln -s ../../owners/owners* .
+   $ ln -s ../../owners/owners .
+   $ ln -s ../../owners/owners-autoassign .
    $ ln -sf ../../owners/external_plugin_deps.bzl .
    $ cd ..
-   $ bazel test plugins/owners-common:test
+   $ ln -s ../owners/owners-common .
    $ bazel build plugins/owners plugins/owners-autoassign
 ```