add Dockerfile for testing

Dockerfile

@@ -0,0 +1,26 @@
+ARG PYVER
+FROM python:${PYVER}
+
+ARG PYVER
+ENV PYVER ${PYVER}
+RUN apt-get update -y && apt-get install -y openbabel libopenbabel-dev swig && \
+    ln -s /usr/include/openbabel3 /usr/local/include/openbabel3
+
+ARG PACKAGE
+ENV PACKAGE ${PACKAGE}
+RUN echo ${PYVER}
+COPY ${PACKAGE}/requirements/ubuntu-latest_py${PYVER}_extras.txt ./requirements.txt
+
+RUN python3 -m pip install --upgrade pip pip-tools && \
+    python3 -m piptools sync --user requirements.txt
+
+COPY ${PACKAGE} ${PACKAGE}
+
+ARG API_VERSION
+RUN SETUPTOOLS_SCM_PRETEND_VERSION=${API_VERSION} python3 -m pip install --user --no-deps -e ${PACKAGE}
+
+RUN mkdir tests
+COPY tests/conftest.py tests/
+COPY tests/test_files tests/test_files
+COPY tests/${PACKAGE} tests/${PACKAGE}
+CMD python3 -m pytest tests/${PACKAGE}