Azure/GitLab/Travis: Add SPL unit tests

Run SPL unit tests in all test environments.

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/.travis.yml b/.travis.yml
index fb8f731..cb48ff3 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -512,7 +512,7 @@
     - name: "test/py sandbox_spl"
       env:
         - TEST_PY_BD="sandbox_spl"
-          TEST_PY_TEST_SPEC="test_ofplatdata or test_handoff"
+          TEST_PY_TEST_SPEC="test_ofplatdata or test_handoff or test_spl"
           TOOLCHAIN="i386"
           TEST_PY_TOOLS="yes"
     - name: "test/py sandbox_flattree"