Add scala tests to CI

--
Change-Id: If286a9718e036d2bd555baf78600e9208ba5a990
Reviewed-on: https://github.com/bazelbuild/bazel/pull/872
MOS_MIGRATED_REVID=114563576

compile.sh

diff --git a/compile.sh b/compile.sh
index bf13174..3a0869a 100755
--- a/compile.sh
+++ b/compile.sh
@@ -154,6 +154,7 @@
       ${EXTRA_BAZEL_ARGS} \
       --javacopt="-source ${JAVA_VERSION} -target ${JAVA_VERSION}" \
       -k --test_output=errors //src/... //third_party/ijar/... //scripts/... \
+      //tools/build_defs/scala/test/... \
       || fail "Tests failed"
 fi