Alpha value potential fix

[InesGP]

potential fix for #40 I noticed that the values for alpha were hard coded in the main.py, so I expanded alpha from a single value into the three values used for MF, BP and CC and then inputted them into the already existing alphas dictionary. I also included a Jupyter notebook detailing a few test runs with different alpha values and their Jaccard similarity score as well as the Dockerfile I used to create the environment to run the DeepGOPlus code in the issue associated with this PR.