Update requirements specifications

[sandervh14]

Task Title

Task: Update requirements specifications

Task Description

Right now, our requirements.txt only lists the required packages, not a python version. It takes some "figuring out" (searching on PyPi for supported versions of the dependencies, e.g. https://pypi.org/project/scikit-learn/) before knowing which python version to install on a fresh conda environment before being able to use Cobra.

Therefore:

• add a badge for the supported python versions on our readme.md page (= our main github entry page), like done on https://pypi.org/project/scikit-learn/ and similar to the PyPi badge we have now already.
• add a conda_env.yml in our repo too, for fast creation of a conda environment.

  conda create -n cobra python=3.x # adapt me with minimal python version
  conda activate cobra
  pip install -U pythonpredictions-cobra
  conda install ipykernel ipywidgets jupyterlab # (*)
  ipython kernel install --user --name=cobra
  conda env export -f conda_env.yml

  (*) ipykernel to register the conda env as a jupyterlab kernel if jupyterlab is already installed, the other two because of the tqdm warning: TqdmWarning: IProgress not found. Please update jupyter and ipywidgets. See https://ipywidgets.readthedocs.io/en/stable/user_install.html.

• update the installation instructions in the readme.md to specify at least as well the fast creation of a conda environment (with conda env create -f conda_env.yml or manually with the above instructions, and add that the python version can be increased depending on the client's infrastructure specs), and ideally cover all required readme topics as described in https://gist.github.com/kipyegonmark/89fe62493f22d93705d917d634d8eeb2.