Split replication plugins tests in two groups

Run unit-tests and integration tests in parallel by splitting
them into two separate tasks.

This also allows to potentially identify which group of tests
is flaky, because Bazel would flag one or the other in case of
instability.

Change-Id: I21f969a17e3653dfc5ab93d71cc6955024fc2d8f

BUILD

diff --git a/BUILD b/BUILD
index 50615d8..72a3fc8 100644
--- a/BUILD
+++ b/BUILD
@@ -23,6 +23,18 @@
     name = "replication_tests",
     srcs = glob([
         "src/test/java/**/*Test.java",
+    ]),
+    tags = ["replication"],
+    visibility = ["//visibility:public"],
+    deps = PLUGIN_TEST_DEPS + PLUGIN_DEPS + [
+        ":replication__plugin",
+        ":replication_util",
+    ],
+)
+
+junit_tests(
+    name = "replication_it",
+    srcs = glob([
         "src/test/java/**/*IT.java",
     ]),
     tags = ["replication"],