Documentation update

[jklenzing]

Closes #69, #94, and #153.

Summary of changes

• Added instructions to list files in new_instrument.rst (C/NOFS IVM list_files #69)
• Added description of sat_ids to new_instrument.rst (Documentation lacks information on sat_id functionality and use. #94)
• Scrubbed code in demo files (pep8, python2 -> 3)
• Updated code in tutorial.rst and examples.rst (documentation bugs #153), making examples consistent with demos
• Updated images for examples.rst, using Perceptually Uniform Sequential colormaps
• Updated discussion of commands in documentation taking into account the utils reorganization in Utils restructure #164

[coveralls]

Coverage remained the same at 76.648% when pulling 267b79f on documentation into ed3c512 on develop.

[jklenzing]

Direct links to changed documents:
https://github.com/rstoneback/pysat/blob/documentation/docs/examples.rst
https://github.com/rstoneback/pysat/blob/documentation/docs/new_instrument.rst
https://github.com/rstoneback/pysat/blob/documentation/docs/tutorial.rst

[aburrell]

Other comments relate to content of new_instrument.rst:

• Supported Data Templates should include Madrigal
• A section with a list of the optional, but standard inst routines should be added.
• Where and how to add data acknowledgements should be added.

[jklenzing]

Other comments relate to content of new_instrument.rst:

* Supported Data Templates should include Madrigal

Added. Madrigal currently does not use functools.partial. Is this something we should update?

Writing up documentation for current methods.

[jklenzing]

Updates completed. We should have a larger conversation about how the acknowledgements are implemented.

[rstoneback]

I noted an area that needs tweaking, but otherwise looks good.

I was a bit surprised myself that the madrigal code didn't use functools. I don't remember why that is. Updating it would improve style consistency but wouldn't change overall functionality.

[jklenzing]

Updates to madrigal are out of scope here. Adding a note to #106.