JOSS: Review install guideline

[glemaitre]

Couple of points to address:

• I don't think that you depend on argparse since it is in the standard library.
• You should as well mention that you support Python 3.5+
• Is there a reason for the package to not work cross-platform. All packages installed with conda should work under MacOS and Windows.
• I would remove the install_requires from the setup.py since the opencv package will be installed from pip even if it was installed with conda. You can instead create a requirements.txt for the PyPi folks.
• The statement Place the downloaded ... is not correct for all environment and depending of the way that you installed the software.

[maxrousseau]

These issues have been resolved:

• removed argparse
• it has not been tested cross platform which is why i did not include it
• i removed install_requires and replaced it with requirements.txt
• fetcher.py function replaces the large file download
  can we close?

[arokem]

@glemaitre : can this issue be closed?

[maxrousseau]

@glemaitre, @arokem: I believe this has been adressed, closing.