Add Dockerfile, gitlab-ci

Dockerfile

@@ -8,16 +8,11 @@ FROM python:3
 # Here we update the image and add python3 virtualenv
 
 RUN apt-get update && apt-get upgrade -y && apt-get install \
-  -y --no-install-recommends python3 virtualenv
-
-# Create a virtualenv for the application dependencies.
-# # If you want to use Python 2, use the -p python2.7 flag.
-RUN virtualenv -p python3 /env
-ENV PATH /env/bin:$PATH
+  -y --no-install-recommends python3
 
 # Install pip dependencies
 ADD requirements.txt /app/requirements.txt
-RUN /env/bin/pip install --default-timeout=100 --upgrade pip && /env/bin/pip install -r /app/requirements.txt
+RUN pip install --default-timeout=100 --upgrade pip && pip install -r /app/requirements.txt
 
 # We add the current content of the git repo in the /app directory
 ADD . /app