Docker: Add ci-otio image (#1278)

This includes both, the Python and C++ version. We basically just need the headers and libopentime(line).so

* Add label for VFXPLATFORM_VERSION
* org.opencontainers.image.licenses defaults to GPL-2.0-only?!

docker/scripts/build_otio.sh

@@ -0,0 +1,23 @@
+#!/usr/bin/env bash
+# Copyright (C) 2020 Olive Team
+# SPDX-License-Identifier: GPL-3.0-or-later
+
+set -ex
+
+git clone --depth 1 https://github.com/PixarAnimationStudios/OpenTimelineIO.git
+cd OpenTimelineIO
+
+#if [ "$OTIO_VERSION" != "latest" ]; then
+#    git checkout "tags/v${OTIO_VERSION}" -b "v${OTIO_VERSION}"
+#fi
+
+pip install --prefix="${OLIVE_INSTALL_PREFIX}" .
+
+mkdir build
+cd build
+cmake .. -G "Ninja"
+cmake --build .
+cmake --install . --prefix "${OLIVE_INSTALL_PREFIX}"
+
+cd ../..
+rm -rf OpenTimelineIO