Refactoring notebooks

[iled]

Hey all,

Following the lead by @eeholmes, I have started to refactor code out of the notebooks. The goal is to extract code that can be reused elsewhere.

For now, these efforts are being done in the refactoring branch. Note: this tutorial of the hackweek has more info on branches.

Notebooks whose functions have been refactored so far:

• [x] DataDownload/OpenAltimetry_example.ipynb by @eeholmes
• [x] DataDownload/SlideRule_example.ipynb by @eeholmes

TODO:

• [ ] improve docstrings (documentation in the code, see coastal/plot.py/plot_from_oa_url for a good example)
• [ ] refactor code that was not in functions defined within the notebooks but that can be moved to one
• [x] rewrite the notebooks to use the functions already refactored and test them

This issue will be updated as more notebooks are refactored.

[iled]

092e1aa removes def's from the two first refactored notebooks and imports those functions from the local modules. Outputs are confirmed to be the same, so those functions seem to be ready to be used!

[iled]

As of ee2fe74 (4 commits), two more notebooks had defs refactored out:

• DataDownload/SlideRule_getData.ipynb by @eeholmes
• contributors/NoelleHelder/AK_topobathy_vis.ipynb by @nkhelder

Additionally, refactored notebooks were moved to ./examples, which can later be renamed according to discussion in #6