Update dockerfile install of poetry + separate directory copies

Dockerfile

@@ -1,8 +1,9 @@
 FROM python:3.8 AS xaitk_base
 
 # install poetry and configure to install to pip environment
-RUN pip install poetry \
-&& poetry config virtualenvs.create false
+ENV PATH=/root/.local/bin:${PATH}
+RUN (curl -sSL 'https://install.python-poetry.org' | python3 -) \
+ && poetry config virtualenvs.create false
 
 WORKDIR /xaitk
 
@@ -11,5 +12,9 @@ COPY poetry.lock pyproject.toml /xaitk/
 RUN poetry install --no-root
 
 # install package
-COPY . /xaitk/
+COPY docs /xaitk/docs/
+COPY scripts /xaitk/scripts/
+COPY tests /xaitk/tests/
+COPY xaitk_saliency /xaitk/xaitk_saliency
+COPY .flake8 .mypy.ini CONTRIBUTING.md LICENSE.txt README.md /xaitk/
 RUN poetry install