Script to run tests (eg. in CI)

We'll incrementally add more tests as we progress. Not everything will
need testing.

tts/test.sh

@@ -0,0 +1,18 @@
+#!/bin/bash
+
+set -euxo pipefail
+
+TEST_VENV_DIRECTORY="./python"
+
+# NB: "python" is the name of our virtual environment python directory.
+if [ ! -d "${TEST_VENV_DIRECTORY}" ]; then
+    python3.6 -m venv "${TEST_VENV_DIRECTORY}"
+fi
+
+source python/bin/activate
+pip install --upgrade pip
+pip install -r requirements-tacotron-python36.txt
+
+# Run tests in modules that support tests
+pytest text -vv
+