API cleanup

[ethanwhite]

I have a couple of suggestions for cleaning up the API to make it more consistent. I'll demonstrate the suggested changes using the CLI, but I think we'd also want to make similar changes to the Python interface for consistency:

• install python_libraries -> install python-packages
• install minicran -> install r-packages
• add-packages r package1 -> add-r-packages package1
• add-packages python package1 -> add-python-packages package1

An alternative to the last two changes, if we thought we might want to do something similar for lessons, would be:

• add-packages r package1 -> add r-packages package1
• add-packages python package1 -> add python-packages package1

which would then allow:

• add lessons url1 url2

Thoughts?

[garezana]

This is definitely an improvement, particularly the change from "minicran" to "r-packages." After reading this, I realized that the user base may not be familiar with or utilize minicran. It is unnecessary to make users write this prompt explicitly.
In my opinion, using the format add python-packages package1 is more intuitive as it clearly separates the action of adding from the desired content.

[ethanwhite]

@garezana - you had indicated that you were working on this. If you are can you provide an ETA. If not I'm happy to take care of it.