Add python server dockerfile and requirements

PythonServer/Dockerfile

+FROM python:3.7-slim
+
+RUN groupadd -r -g 1000 csi \
+  && useradd --no-log-init -r -g csi -u 1000 csi \
+  && mkdir -p /var/www/data \
+  && chown csi:csi /var/www/data
+
+# Install required dependencies
+RUN apt-get update \
+  && apt-get install -yq --no-install-recommends \
+    git \
+  && apt-get clean \
+  && rm -rf /var/lib/apt/lists/*
+
+COPY requirements.txt /requirements.txt
+RUN python3 -m venv /venv \
+  && . /venv/bin/activate \
+  && pip install -i https://artifactory.esss.lu.se/artifactory/api/pypi/pypi-virtual/simple --no-cache-dir -r /requirements.txt \
+  && chown -R csi:csi /venv
+
+COPY --chown=csi:csi pos-python-server.py /app/
+WORKDIR /app
+
+ENV PATH /venv/bin:$PATH
+
+USER csi
+
+CMD ["python3", "-u", "pos-python-server.py"]

PythonServer/requirements-to-freeze.txt

+GitPython
+matplotlib
+numpy
+pyepics
+py-epicsarchiver

PythonServer/requirements.txt

+certifi==2019.3.9
+chardet==3.0.4
+Click==7.0
+cycler==0.10.0
+gitdb2==2.0.5
+GitPython==2.1.11
+idna==2.8
+kiwisolver==1.1.0
+matplotlib==3.0.3
+numpy==1.16.3
+pandas==0.24.2
+py-epicsarchiver==0.3.0
+pyepics==3.3.3
+pyparsing==2.4.0
+python-dateutil==2.8.0
+pytz==2019.1
+requests==2.21.0
+six==1.12.0
+smmap2==2.0.5
+urllib3==1.24.2