Add python-dev, build-essential instal for SL tests

Change-Id: Ia83ec28aa37e2a2851f7a3a08a66b59cbb5e15e8
diff --git a/tcp_tests/templates/shared-sl-tests.yaml b/tcp_tests/templates/shared-sl-tests.yaml
index 35af573..6b5ab87 100644
--- a/tcp_tests/templates/shared-sl-tests.yaml
+++ b/tcp_tests/templates/shared-sl-tests.yaml
@@ -25,6 +25,7 @@
 - description: Configure tests
   cmd: |
     set -e;
+    apt-get install -y  build-essential python-dev;
     . venv-stacklight-pytest/bin/activate;
     stl-tests gen-config-mk;
     cp venv-stacklight-pytest/lib/python2.7/site-packages/stacklight_tests/fixtures/config.yaml /root/stacklight-pytest/stacklight_tests/fixtures/config.yaml;