Get examples.ipynb working

[clmould]

Description

Fixed problems within examples folder. The original input file that examples.ipynb was trying to use did not exist, so gave it a new input file. The scan.ipynb file did not have an input file so one was added. The csv_output.ipynb file also did not have an input file, so added one and also changed the list of variables that would be added from the input file to the created csv file. Also added a test for csv_output.py which tests that a csv file is created and that the values read in from the input file are all positive floats.

Checklist

I confirm that I have completed the following checks:

• I have justified any large differences in the regression tests caused by this pull request in the comments.
• I have added new tests where appropriate for the changes I have made.
• If I have had to change any existing unit or integration tests, I have justified this change in the pull request comments.
• If I have made documentation changes, I have checked they render correctly.
• I have added documentation for my change, if appropriate.

[jonmaddock]

Just an assertion addition to the CSV test please!

[jonmaddock]

Looks great Clair. A couple of the asserts in the CSV test could be made a bit more concise, but I'm more than happy with everything else in this PR, so I'll merge it. Great!