Dockerfile has been updated

[koustav-pal]

The previous Dockerfile images did not allow execution of post-processing scripts. Therefore, the dockerfile has been updated to allow the execution of screen.py, outliers.py and postprocessing.py.

Furthermore, python installation has been added with corresponding versioning.

[lfearnley]

Hi @koustav-pal! We originally hadn't included the post-processing scripts in that Dockerfile in the hopes that it would reduce the image size when scaling up. Let me check what the image size differences are and I'll merge if they're not significantly different.

[lfearnley]

Oh, also, two minor things:

3a816db changes the repo from the superSTR repo to your fork of it as well as updating the path; please correct this.

Could you please split your changes to the dockerfile and your updates to screen.py into two separate pulls?

Thanks!