readme: updated to include process-dependency-links option

[adrianherrera]

We need to update the docs to include this process-dependency-links option.

I was just trying it out, and noticed that:

DEPRECATION: Dependency Links processing has been deprecated and will be removed in a future release.

We can achieve the same thing with the following requirements.txt file and removing install_requires from setup.py:

# S2E engine requirements
docutils
pygments

# s2e-env requirements
enum34
jinja2
pefile
psutil
git+https://github.com/s2e/pyelftools.git#egg=pyelftools==0.24s2e
python-magic
pyyaml
requests
sh
termcolor
pytrie

The downside of this is that it adds an extra step: a pip install -r requirements.txt before the main pip install . However, I think I prefer this method, regardless of the extra step, mainly because of the deprecation notice.

Thoughts?

[vitalych]

I've seen this alternative and decided to stick with the deprecated option, because it's simple. It has been deprecated for a very long time now but hasn't been removed yet because they still didn't implement a proper alternative.

pypa/pip#4187

[adrianherrera]

Ok, sounds reasonable to me :)